Lot of good tips here, but one I didn’t see (and also personally regretted not doing), is empty your backpack every time you return to town. Disassemble the gear you’re not going to use and either do you’re crafting or bank the materials for later. You will pick up tons, and I mean tons of useful crafting materials and goodies. But wasting half of more of your bag space holding onto stuff you don’t use while questing/fighting means having to either stop in the middle of good time to return to town and make space or having to stop and destroy the items. Do yourself a favor and only leave town with the things you’re going to use and you will not need to face these dilemmas, and have more time out there having fun.
P.S. If your bank gets full you can make more space easily by creating new characters, skip the into, and run straight to the bank. Since you have a shared bank between your characters you can just log into your banker characters and hold onto the excess that wouldn't fit in the bank.