I work in very high resolution (10k pixels) so I can be less pedantic about dropped pixels when I fill colours. Small white areas that don't get filled usually disappear by the time I resize it back down for web.
Working in Clip Studio, that also offers a couple of conveniences I haven't found in other programs (came from Paint Tool SAI, Firealpaca/Medibang)
- various preset balloon shapes, so I can just drag and drop onto my comic when I'm typesetting. CSP also has a really good text function where you can insert text into a balloon shape, and the text will lock to the balloon, allowing you to move both around at the same time with only the balloon selected.
- CSP's vector layers are really good for expediting lineart, you don't have to make sure every stroke is perfect any more and you can just erase stray intersected lines.
- the fill tool in CSP is the best I have used of all the art programs I've used in my career, and it has various other fill tools that help save a lot of time.
- the combination of perspective rulers and 3d models is very powerful in CSP, allowing me to draw complicated angles accurately.
I know this sounds like an advert for Clip Studio LOL, so I'm sorry, but it genuinely is the best drawing software I've ever used in my life, and upgrading to it last year was such a game changer.