You didn’t mention if it was raw or with a match bonus? If raw, i would start with the more easier bonuses such as steam tower, wild north, golden colt or what ever it’s called and then move up to some of the more popular slots in bonus hunts. Temple quest spinfinity is sometimes easy to bonus if it’s in the mood.
As far as I can remember, novomatic and red tiger don’t save, so will just update your balance as soon as you close the slot. Yggdrasil only saves for 20 minutes or so.
If you’re playing with bonus cash, check with the live support first to see if it’s okay – I’ve seen a few streamers get bollocked for it, and then their balance gets forfeited. If you’re playing with cash, good luck! Let us know how you get on.