Using a variety of girls from events, gacha, and several 6* guaranteed offers, this is what My Set 1 ended up like:



I don't see myself changing it much anymore, each squad synergizes pretty well with itself.
The only girl left on my wishlist would be Anemone, she'd fit perfectly in team 3 to replace Strawberry Candle, who I'd move to team 2 to replace Chocolate Cosmos. That would turn team 3 into a pretty badass counter-squad, and team 2 in an alternative Solar Squad.

I have Peach, who I could put into such a Solar Squad as well, but I find her voice terribly annoying, so I removed her from the roster. Dawgwud and Leucocoryne would benefit from the increased amount of solar blasts regardless of what team they're in, so they're fine where they are now.