How to fix a splotchy bleach job?

You could do a mild bleach bath just on the parts that don't seem to have lifted if you're confident doing that without touching the rest. If Not then yeah, I would say applying first to those bits would probably work.

Thanks!

I'm curious: were my ratios off? Also, how long should I wait before I do a touch-up? I don't want to screw it up again, haha.

That sounds like the ratio I normally use, I would try mixing the bleach powder ans developer together before adding the shampoo to avoid lumps. That's what I usually do.
You should wait two weeks between bleach baths for yoyr hair to be healthy. Also putting coconut oil on your hair before bleaching will help the condition a lot. (if you don't do that already, Not being patronising!)

I did! It helped a lot--as did the sensitive scalp developer (totally worth the extra $). I smothered my hair in coconut oil right after I got out of the shower as well. I have no idea why I didn't use it before now, my hair is so soft.

Again, thanks so much for your help. 😀

Ooh I didn't even know you could get sensitive developer! I'm definitely going to look in to that as my hair absolutely hates bleach.
Also it sounds like you're doing everything right with your hair, good luck evening the colour out 🙂

Was your hair virgin when you bleached? if so, the unevenness is due to the application. You need to section your hair and make sure each strand is fully saturated, so use plenty of product. To even it out, apply to the darkest areas first, and only apply to the lighter parts (if necessary) when the dark part has already lifted to the same shade. It is very fiddly, you will need someone to help you. Do a strand test to check the timing.
Remember that bleach is at its most effective when first mixed, so aim to get it on as quickly as possible

Yeah, it was virgin. I had a huge problem with sectioning. My hair is past my chest and I only had hair ties. It was a big mess, all in all. Haha.

If you have a lot of hair it can be a lot easier to only bleach half at a time. I would do the under section, then the top. That way you aren't rushing to get it all done.

Thank you! Hopefully I won't have to do that next time, but I'll keep that in mind. I have very thin hair (both in volume and in thickness of hair) so I didn't think I'd need as much bleach as I used and I could do it all at once by myself. I was so very wrong. I'm learning so much this week.