This is a,lot of good advice, but I'd like to add on to the pass-turret point.
Handing over an outer turret can be an incredibly powerful strategic decision. I recently played a game where I gave up CS and a turret, but by watching jungler patterns and waves I managed to incur 3 kills and 2 turrets.
A lot of people consider losing turret something taboo, especially below gold. And to give it up for no reason, sure that's bad. But instead of dying under turret you have, the way I see it, three options:
A) Give up turret, stay in lane. Let the waves push, and freeze just behind the rubble that was your tower. You now have a very safe place to farm, and the freedom to ward around river and in the jungle between waves.
B) Shove lane, farm Jungle. This is typically the wrong answer, honestly. Some champs can clear jungle quickly and safely, but most run out of steam somewhere. This also tilts some jungles (generally low), so be wary. But when it works, you can drink in XP and gold at an incredible rate.
C) Shove, and roam. This is a hard one to recognize, but can be far more effective. Mind the lanes near you, and watch for the wave to start pushing towards your team's tower. When it turns that way, shove your lane out and go help them. Done right, you can delay your own turret falling long enough to take one other. Be mindful of the enemy jungler when doing this, though, and try to stay on top of wards.
to do so though, just in case.
