Once you find gear you like, avoid exploring every room and just find the stairs. Also, don't get cornered as it is an easy way to end a run! Also learn the attack and movement patterns of all the enemies. Give all of the types different names to help you remember what they do. And you do find extra gear, just salvage it unless it's a better version of something your have for gear. Let me know if this helped!
Note: spears are the most op weapons in the game in my opinion because of reach, which allows you to attack from 2 squares away
Also, try to make ability combos. Ex: throw a spear and then pull them with Singularity, making the enemy take damage from the spear and Singularity at the same time. Or, Meteor Strike and Blizzard. You decide the combo.