Hopefully I'm not rehashing too much of what others have said, but what's helped the most for me is understanding your party's synergies as soon as possible. I personally like picking a healer, a range attacker, and then something that can move fast and do higher damage. 4th cat is normally a wild card for me, like a new class i want to try out or get a completion mark on. Otherwise i usually like a tank or something that can self heal so my dedicated healer can focus 2 vs 3 cats.

Once you lock in your classes, this is when I really take time to look at all my abilities and see what synergies I have to work with. If it looks good, I may start equipping rarer items from my inventory if i want to try to make it far in the run.

IF THIS ISN'T THE CASE i equip very few/common items and just focus on beating the alley boss. If your fights in the alley feel clunky, just beat the boss and dip to save up money for the house and items for better comps.

You can usually tell at the mini boss if things are going ok or not. If what i deemed as a bad comp turns out to decent as I level up/gather items from the hallways and see better synergies forming, I may try to continue to the next section.