A good floating line
, about 3/8 and 3-400 feet long usually suffices. In some spots it's enough length to allow going through a ring or around a tree and bring the line
back to the boat so you can release it without going ashore, at other times you'll simply tie it off.
BTW if you do tie around a tree, try to put a secure loop of old line
loosely around the tree and run your shoreline through that - it avoids "sawing" through the bark as the boat swings or as you pull the line
In many BC marine parks there are eyebolts installed in the rocks ashore for easy tie up spots. They are usually flagged by a slash of bright orange or green paint
This is common practice here, as the depths are sometimes excessive and/or the cove too small (or too crowded) for adequate scope and swing room.
Just be sure that you avoid, if you can, a situation where you have strong wind, and/or (especially) tide across the stern-tied boat.... The loads can get extreme in a hurry and the anchor
is the weak point. If it lets go then your stern line drags you right onto the beach. Tie it in such a way that you can slip it in a hurry if you need to. This is rarely a problem though, and stern tying is, as mentioned, very common.