Got to level 34 before I got bored of my perpetual strat. The gist of it is that when you play a card from the same spot (like always play the card at spot 1/2/3/4 numbered left ot right) you will always draw cards in the same order with the order being the same as you played. The only way to reorder is to play a different spot since newly drawn ones always come fill spot 4. This changes the size of your "effective deck", if you always play spot 4 its smaller (and the cards unused are always in hand) and if you play spot 1 its at the max size. The other cards can be considered filler cards. I think for safety its best to play 3/4 unless you are reordering since on level up you need to swap a card, and swapping is potentially dangerous when you built a good effective deck so its good to have filler cards to sacrifice if need be. Note that you have to reorder them every time you level up.
Using this you can set up a number of effective decks based on not running out of energy. You need a way to clear the screen and to refill energy. My last run cleared screen with bounce + peirce since there are a lot of ways to set this up and its useful to have early game before you can do all the setup. Other ways could be to use love + peirce, and maybe bombs. For energy refill your best shot is just using an energy refill card and making sure you spend ~5-6 energy cycling through the effective deck, making sure to order the energy refill right as you run out. You can also possibly stall with enough freezes, just playing them at a rate of about 1 every 2 seconds. Ideally you use a mix of both. Other strats that might work would be getting really high power cards and the perk for all cards cast for 1, and maybe something with shuffling costs but those are more risky and harder to do.
All this sorta hinges on the fact that you get cards back in the same order as you play them, once you wrap your head around how to structure an effective deck with that in mind you can generally build an perpetual strat pretty easily. I think as long as you can reach level 10. My last run I cycled the effective deck with 2 freeze (though I only needed one) 2 energy (again only needed the one) 2 quad peirce (I needed both) and piercing shots bounce perk. Before that I got to ~30 with bouncing shots peirce perk, 1 energy, 1 shoot X times, 1 bounce and a couple free cards that I just used to buffer space. For both of these I generally tried to play from spot 3 so I could reorder on the fly, but for my most recent strat I found that playing from spot 4 is just easier to not accidentally misclick. I guess if you play keyboard you don't really need to worry about that.
And got another good combo: freeze, next shot love, bouncing, energy refill, bouncing, and bouncing pierces perk. Always play from 4 after the initial reordering and pause before playing freeze to wait for the screen to fill up to about half. The other cards are for swapping.