I've been looking to get into yuri/shoujo-ai recently, but the ones that I've tried aren't really to my taste, because I rather like relationships with a clear dominance in one person. It doesn't have to be sexual dominance (although that's very welcome too 😉 ), but just something that doesn't seem like a bland schoolgirl romance. I guess I'm looking for something set up more like a yaoi manga, but with females. Any suggestions? 🙂

I don't read a lot of yuri/shoujo-ai (unfortunately), but I went to my complete and reading list to see what mangas could fit what you are looking for.

Yukemuri Sanctuary has this seme x uke relationship when they are having sex, I guess. There is always someone more experienced who takes the lead. Sweet Guilty Love Bites follows the same path... Your Love.
Maybe This Is a Great Hug Pillow also?
Asagao to Kase-san., tomboyish x girly.
Citrus (Saburouta), pushy.
Collectors, "tomboyish" x girly.
Raubritter*, more like two semes having fun with a innocent uke. haha
Kuchibiru ni Suketa Orange, innocent girl x popular one (for me, it has the "uke x seme" feeling, since the innocent girl is all dreamy about the other, normally the uke is innocent and in love with the stoic seme).
Orange Yellow falls under the category of "tomboyish x girly" and not really uke x seme, but there is the stoic x innocent contrast too, so maybe?
Himitsu no Hanazono (FUJII Mihona), tomboyish, old school drama shoujo, haha.
Ebisu-san to Hotei-san, stupid x stoic, not uke x seme, but a good read.
Cirque Arachne, stupid x stoic, not uke x seme, but a good read.
I think I'm recommending my entire yuri list...
Knife Edge Girl, tomboyish x girly, not uke x seme, but a good read.
Kawaii Anata, two tomboyish x girly oneshots (ch. 2 and ch. 4 I think).
Sasameki Koto, stoic x stupid.
Hana to Hoshi, stoic x stupid (it reminds me of the love and hate relationship in SekaKoi).
All Safe! Love X Love, sexual dominance.
Gokujou Drops, sexual dominance.
Lonely Wolf Lonely Sheep, tomboyish x girly.
Clover (OTSU Hiyori), tomboyish x girly, ch. 2.
Hanjuku Joshi, oneshot ch. 1 I think, tomboyish x girly.

I hope you like at least one of them. I think some of them fall into "bland schoolgirl romance", but since they are short, you could give it a try.

Thank you! I'll definitely give those a try 😀

A few oneshots come to mind

Drip by Amano Shuninta
Honey & Mustard

As far as series go.... anything by Rokuroichi has that whole uke/seme setup.
Shoujo Sect has the aggressive leader of her harem
Hanjuku Joshi is about two girls, a feminine one and a more tomboyish one and the tomboy begins their sexual relationship. The manga is 90% sex