Since the last FAQ page mysteriously disappeared (and I still can't figure out why) here is the new one. It is a summary of the community's favourite ways of obtaining/storing etc... their caps. If you want to add to it just comment below.

Obtaining:

Trading in person. Use Crowncaps.info to find people near you and organize a meetup -u/Legoking

Trading online, also through Crowncaps.info -u/LordBottlecap

Recycling centers -u/LordBottlecap

Antique shops and breweriana shows -u/LordBottlecap

Local classified ads like Craigslist or Kijiji (Canadian) -u/Legoking

Soda shops and ethnic grocery stores -u/LordBottlecap

Asking the waiter at a restaurant or bar -u/Redneckromeo22

Have friends bring some back when they travel -u/LordBottlecap

Ebay, just be careful because there are a lot of fakes there.

Go to a brewery and ask in person -u/Legoking

Identifying:

The Holy Trinity: Crowncaps.info (CCI), Bottlecapindex.com and BottleCapClub.com (CCSI). CCI is the most expansive with the most users, and gets dozens, sometimes hundreds of caps added to the database daily and has an advanced search feature. Bottlecapindex tends to be useful for finding caps with no text on them, since your search keywords also check the physical description of the cap. BottleCapClub.com is comprised mostly of American collectors and it has many American cork-lined caps which are not in CCI and has more information on breweries and bottlers than on CCI. -u/Legoking

Post on your country's bottle cap forum. If you go to Crowncaps.info, and look in the top left corner there is a link to a forum of the language that you have CCI set to. Ex: if you have CCI set to Polish mode, the link displayed will be the link to the forum for collectors in Poland. -u/Legoking

If you can't find it still, you can post it in this subreddit for help. -u/Legoking

Cleaning:

Use warm soap and water to rinse the cap, and let it dry overnight. -u/JDStap12

Needlenose pliers; stacks of various-sized coins, taped together, placed flat-side-down on an upside-down cap on a hard, flat surface. Apply hammer. u/LordBottlecap

For modern caps with sticker residue: Use a wet cloth to remove as much of the glue as possible. Use a dry piece of fabric to rub off the rest of the glue. It will come off if you press hard enough -u/Legoking

Goof Off for removing glue residue -u/LordBottlecap

Storing and displaying:

Acquire dime-sized magnets, then attach them to your caps and fridge/magnet board/etc -u/KillCornflakes

Remove the inside part of a CD case, and it will perfectly fit 4x4 caps. u/theunexpectedmango

Attach Velcro to caps, which go onto screws, which are screwed onto to painted 2' x 4' plywood boards. Organized -roughly- by continent, country, brewery, style of beer, then age. -u/LordBottlecap

Cardboard flats or large wooden boards with raised edges to keep the caps from falling off. -u/Legoking

Binder with film negative sheets, or coin/cap sheets -u/EncapsulatedPickle

Opening bottles:

Use a lighter.

(Place a quarter over the cap with a napkin under the quarter)[https://imgur.com/OIm0Q5u] -u/theunexpectedmango

Stick a fork or knife or the tip of a scissor blade under each tooth of the cap, one at a time

Use the edge of a table.

This and this -u/JDStap12

https://gropener.com/ -u/Expensive_District_5

https://store.bellsbeer.com/products/bells-reclaimed-wood-cap-saver-bottle-opener -u/mizary1

Now that the FAQ page is back up, I am once again deleting posts which ask questions that are answered in the FAQ. However I will wait one week before I begin to enforce this rule again, because I want to see if anyone replies to this post with more info to add to the FAQ.

u/Legoking