General

Uh you can just solo at stronghold... Don't have to party

You can kill Mutant Pigs or snails. It'd be much slower exp than dipq but you'd be gaining familiar cards that you could merch until you make enough money to get better equips. Then you wouldn't have trouble soloing stronghold.

Other possible options would be to find a place in stronghold where you can spam an attack without getting hit and camp there
Another option is HT as a boss run
Ramaru normal mode is ok exp i guess and u can do zak for fun/or easy mode magnus
Leech with friends if you can

Oh, come on! You'll never defeat the Black Mage with [i]that[/i] attitude! Even our predecessor, Freud, couldn't beat the Black Mage with a FULL PARTY OF GODLIES. Not ONLY did Freud not have a problem with teamwork, but he was the LEADER! The heroes need someone to sustain an organized team despite their motleyness! They NEED a leader! Afrien's teachings can [i]help[/i] you live up to the Legend, but that can only get you so far! All the knowledge in the world can't help you without the right attitude!

You can boss, I don't know how much you hit, but hilla twice a day (easy takes about a min for me) you get an easy 7% from that, doing gollux 3 times a day (again easy) will get you about 20ish % and krexel gets you about 26% at that level, so there you go you've literally done more than 50% in less than an hour depending how much you hit again. and DIPQ is most likely the only place to train at besides stronghold.

unfortunately SH is kinda your best bet for now if you want best exp output. If you want some solo play you could do the voyages in commerci they give you quite a bit of exp

Theres really not anything else you could do...