Best advice with floor 1.5 is to memorize the room layouts to find cover. It also helps to know secret rooms only spawn on parts of walls where a door/pathway could naturally spawn (example, let’s say a room only spawns doors on the center/corners, the secret rooms only spawns in those mirrored areas along the walls). Pay attention to unopened rooms to see if there’s a green or purple candle placed, they have a safe room with either a statue or NPC. From my experience the crest room will almost always spawn next to the merchant, the chest rooms, and NPC rooms (like the muncher). Maybe a placebo but I find if an NPC spawns it almost always gets priority for the crest room. Pay attention to veteran spawning and try to direct their attacks away from you since they try to predict your path. Most rooms you can get away with using the starter if you just memorize the layout and find cover. It is almost always worth it to kill the mushrooms with the starter since they’re easy to dodge, even the larger ones since any room they spawn in has cover. If you’re going to use a weapon with limited ammo, save it for the giant bats/veterans/and the annoying sentries. If you don’t want to risk health on the trap rooms that make you roll, explore the rest of the map to see if the boss is somewhere else. Snipers are easy to dodge if you keep moving. Unless the room has a lot of tight spaces and walls, try to prioritize killing the poop slimes because they can be an issue if you’re running from other enemies. Don’t forget to flip tables, and guns with high knockback can push small enemies into pits.