How to use the sling like a real big boi.
As a sling using archer, you should only ever use pebbles as your ammunition. Lead balls are a limited ammo, and though they are slightly more powerful, they are less infuriating. After all the only reason a good slinger slings is to cause feelings of hatred and rage in tryhards and noobs alike. Think about the angry boner you get whenever you die to a wayward rock after barely surviving a duel.
Using the Sling
The Sling (aka: Flaccid Slingshot) uses incredible kinetic energy to propel skipping stones into the skulls of unsuspecting footsoldiers. Perplexingly, the sling in this game throws rocks farther the longer you charge your shot, which isn't how slingling works. While you can charge your shot, it's not actually necessary. Remember that with an unlimited amount of ammo, your fire rate and accuracy are more important than damage dealt in a single shot. I recommend just lightly tapping the left mouse button once you have your target in range, this causes the sling to fire as soon as possible, this forces you to commit to each shot and keeps you agile. To make up for the slight range loss, just practice arcing your pebbles a bit higher than normal.
What to Pebble
While all classes are open game for pebbling, by far the most prized sling targets are the crunchy classes (Vanny and Knight), you get that delectable *BINK* soundbite, and if you get the coveted headshot, you are rewarded with that wonderful exploding dome. Another reason the crunchies are a preferable target is that they move slower and more predictably than the squishies.
Where to Pebble
FFA, TO, LTS, it doesn't matter, always go for targets that are engaged in a fight, they don't see you, they're most likely already low on health, and it's just the best way to enrage random innocent players. Remember that you are a pebble archer, you have no need for honor or dignity, you just want to skip stones off the heads of people with actual skill.
When to Pebble
A wonderful bit of advice for the up and coming pebble meister is to take your time on your shots when necessary, if your target is aware of you they will try to zig zag and close the distance between the tip of their weapon and your soft virgin butt meat. Try to wait until they make a move you can predict, then fire. Try not to fire at enemies who are on the move; rather, fire when they are resting or trying to ward off other players. For shield knights, wait until they have their sword arm facing you, as the shield will block shots even when it's not being held up.
Maximize Your Cancer
To really be an annoying pebbler, try these techniques...
Spam a misleading voice emote such as "Retreat" or "Sorry" the entire time you play, no matter what. This will increase your annoying presence threefold.
Use your sling to kill your target from point blank range, by refusing to draw your secondary weapon you solidify your place on the server as the drooling kissless sped that you truly are.
Target a single player more than anyone. Really get those chicken tendies roasting with your dank pebble skills as you sneak around the map and pick on the same player for the entire game.
Never shut up in chat about how much you hecking LOVE pebbles, your life is throwing rocks from a distance, it just gets you hot an bothered when the chat isn't filled with talk about slings. This will really increase your popularity among the morbidly curious onlookers of the game.