One hundred different ways you can recharge that magic item of yours!
Hold it under flowing water for 30 minutes.
Hold it in direct moonlight for 30 minutes.
Yell at it in anger. (Charges twice as fast during combat.)
Whisper 'I love you' into it.
Throw it in the air as high as you possibly can.
Treat it like the most begrudgingly accepted, and most hated object you have in your possession.
Pack it in the flesh of an undead creature.
Touch a demon with it.
Attach item to a string of three or five feet in length and wave in a circle overhead until string breaks.
Take a piece of shag carpet and rub the item until your hair stands on end or it sparks.
Soak it in Holy Water.
Heat in fire until hot to the touch.
Hug the item close and whisper to it as if a lvoer to 'please come back'. (Much better if sentient and is 'knockec out' when discharged.)
Hold it out away from you until you feel the win take the item away, then chase and catch it back.
Change something in the item for a different color. Example, change the handle wrapping for a differently dyed cord. You can't use the same color again for a week. (The item has a sense of fashion!)
Play a one sided game of chance (Like craps) with the item siting on a chair across from you. It recharges if you win against it.
The item recharges on its own but only if the users apologizes for harming people with it, or helps bury them if killed. If even one victim is left out, the item won't recharge unless the user begs mercy to it for an hour for each victim left behind.
The item recharges after it hurts a dozen of people, with its magic or in some other way. Items that works by charges reload a charge for each person hurt.
Get an mundane item of the same type as the magical one and leave the two touching for 10 minutes. The same mundane item can't be used again.
Shower or bath with the item at hand, equipped or sheated at your side.
Find a way to let the item make a decision for you and stick to it.
Tell the item something you will never do with it, without noting it down, without repeating it and keep your word.
You dream a name often. If you meet someone with that name, without saying a word, hold the item out to them to take it from you, don't resist if they do it. The item recharges at dawn and if it not with you, it appears on your bed.
At any point in your day, put the item in your view and draw it along with the scenery and show the drawing to it.
Lay the item for the night with another item that needs to recharge. They both do so normally.
Smash a coin with the item until it bends or breaks. Any old copper will do and the item suffers no damage from this, ever.
When discharged, the item rusts. Let it steep in water and it will form a poisonus tea that causes nausea for an hour to you, and recharges when you drink it.
Try to seriously bite off a piece of the item.
Kiss someone while holding the item.
Trace it along a star constellation.
Whisper your deepest darkest desire into it.
Bury it and leave it undisturbed over night.
Cut of and tie a strand of hair around it.
Wear it close to your heart for a day.
Stab it into a recently killed body and let it drain the blood for 3 hours.
Throw it as far as you can. Next time you setup camp, it returns to you.
Hold it without letting it go for 2 hours.
Carve the symbol of a Demon Lord into a surface. You take 1d4 psychic damage.
Get some one who doesn’t know it’s magical to kiss it.
Cook it over a flame.
Boil it in blood.
It only actually recharges if people become slightly uncomfortable with the lewd action that you are performing with it.
Cry upon the item.
Physically spin the item for 5 minutes.
Impress the item with a story of personal achievement.
Bring the item to somewhere it has never been.
The item will gain a charge for every 5 seconds it is touching nothing/suspended.
The item will disappear to a hard to find location within 50 feet of the owner. Once it has been found, it will have full charges.
Bathe it in the blood of a monstrosity type creature.
Repeatedly stroke it and call it your 'precious' throughout the day and night.
Hold it lightly between your thumb and index finger, and whisper loving words to it. Loving words must be heartfelt.
Herbs and spices added to dough, which are then wrapped around the item and baked.
The weapon has taken damage from a powerful necromancer. You need to seek a druid grove for a specific plant to coat the weapon in to repair the damage and charge the weapon.
Bury it 10 feet underground for a week to let it absorb some of the earth's (or whatever planet's) power.
Use it as a cooking implement.
Have a gnome sneeze onto/into it.
Treat it to a nice evening at the theater.
Sing to it an ancient song.
Use it as a musical instrument.
Make it the punchline of a joke.
Let the item see you naked.
Intimidate it (DC 15).
Break a piece of it off.
Let someone else use it.
Climb to the top of a certain mountain.
Throw it into a lake, then come back the next day and the lady of the lake will give it back to you.
Kill a friendly NPC.
Kill a worthy opponent alone.
Sacrifice a proficiency and the memories associated with it.
Get into a brawl with an innocent person.
Sacrifice a finger/toe.
Dip it in lava.
Eat it, it will reappear in your hand once you've finished.
Sell it and steal it back.
Feed it. Not blood or souls, just regular food. Set out a plate and goblet. Place weapon or item on the food. Turn away. Food slowly disappears when you aren't looking.
Slightly bend it until you hear a pop and bend no further. Wait for the glow to dissipate before reuse.
Polish with the juice of a rare fruit.
Give it as a gift (permanently).
Rub one side with animal fur, then the other side with silk. (If that sounds like nonsense, google 'friction rod').
Use this instrument to play a song it's never played before.
Let rest the item in a comfy place for 2 hours (or other duration said by your DM).
Using the item in a different way than it's using purpose (like cutting apples with an fiend-killing sword).
Make a tear from a sentient being (or the attuned owner) run from one end of the item to the other (pommel to tip of blade, for example).
It can be left out and naturally covered in dawn's dew to regain one charge.
It needs twenty four consecutive hours of (near) silence to regain one charge.
It can be gifted the user's voice for twelve hours to regain one charge. (This could be like the little mermaid or the item could control your voice, or just the user loses their voice for that time.)
Smells more fragrant the more charges it has. Once a day, if left unwatched in contact with flowers, it will consume them and regain a charge.
As above, but smells more foul the more charges it has, and eats goblin feces.
A silver bird that flies away if released, regaining one charge when it seems to have fully escaped.
Keep it in your mouth for twenty four consecutive hours.
Scar your own body with it.
Give 10% of your party's (non-equipment) wealth to the poor/charity.
Don't eat any food for 48 hours. (First fast attunes the item).
Feed it memories.
Cut a dwarf's beard off with it.
It charges on fear - if someone is feeling scared nearby for one week, it will regain one charge. This time can be split up. (Variant - Focused fear of the item itself has a much greater range, and is worth 7x the charge power, meaning one person focusing on their fear of the item for 24h will give you one charge.)
Polish it to a mirror finish.
Screaming at the top of your lungs at the weapon for 6d10 seconds a day.
Have a long drawn out conversation with the weapon explaining why it should recharge.