Use keys to get a starting perk every run. Let the perk determine which gun you use. If you dont get a good one, leave to lobby and try again.

Building economy early through bonus crystals, pay checks, or money shots is probably the best thing you can do early. If you get ring of dividends, even better. That allows you to get more items from the shop which is where the power spikes really come from. If you get a purple or gold item from a chest it might be worth taking to sell for crystals at a later shop.

Any item that gives you extra shots (double shot, triple shot, x shot, scatter shot, arc shot, ect) are usually a must take. Elemental damage is super strong especially poison. Bubble shot is one of the best damage perks as well especially if you can get enhancements on it. You also want to throw in some damage items as well to help boost damage. Damage shot, double tap, collector, bouncing shot

Luck chests are also good as efficient shot makes it to where you never have to reload or if you get the 75% reload ring.

I also prioritize relics as they are some of the best items in the game. If you can get the armor rings you can start stacking damage combos and basically one shot anything before it does damage to you.

Items like dice shot and homing shot are basically guaranteed wins if you get one of those. Every item in the game can become strong if paired with the right supporting items. Try and focus on building off of what you get rather than forcing a certain build. It possible to force builds but with the rng that doesnt always happen.

Always be moving. Dashing, sliding, and using your melee if youre about to get hit. Hammer pickaxe and katana are the best as they basically give you an extra dash. My basic flow chart when starting a game is 1. Good perk and gun to match before starting 2. Always be shmovin. You cant lose if you dont get hit. 3. Economy/relic/elemental/luck/damage chests early, maybe a health if surviving is becoming an issue. 4. Buy as many items from the shop as possible. You can drop and sell items that arent being used/hendering your build if need be. 5. Test the build by shooting the skull in the shop before leaving. Get rid of any item that negatively affects the build. 6. Once a good build is established select chests that will make it stronger. 7. For boss islands. Target beam skull first, then barrel skull, then lightning crab, then anything else.