oooh okay mate i can Help you with that, its smth ive struggled with a lot during my process
do you thumbnail? thumbnail. a lot. if you dont know what that is, its sketching out different trail designs and layouts and the rest, to see what you like. its trial and error, and its they key to getting something you like, and getting it fast and fun. its kinda like storyboarding for film, i guess? but like, really early storyboards.
first, note down things like:
- what you want to happen in this page
- any dialogue you know you want to include
- anything else too - you might have a particular image you really want, note it down
- other goals. maybe you really want to get some nice backgrounds on this page, or set up something for a future plot point, whatever it is, listing this out helps
then, sketch! i know some people start with pairing expressions and movements to their dialogue and characters - free of panelling and layout and the rest - to get a feel for the page. personally, i keep that stuff in my head and start with layouts - i diddle out three or four boxes and fill them with boxes and circles for speech bubbles, after listing out the four to six panels i wanna get in. but then im working from a really comprensive script, not everyone is.
sketch out each page at least three times - id say do three sketches of different layouts, pick your favourite, and then do three sketches of different visuals within the layout. sketch out your dark & light, do colour tests, all that.
then, when it comes to make the actual page... youre practically tracing, and you know every twist and turn.
it sounds like more work, but its actually all things youre doing anyway - deciding on layout, dialogue, poses, etc - but youre doing it with massive pressure on yourself. if you take the pressure off and just draw messy stuff, experiment with ideas that fail, youll get to an end product youre way more satisfied with, and youll get there easier, and itll be bloody fun. theres no steadfast rules for thumbnailing, so trial and error it and see what works for you 
i hope this helps and i dont turn out to be stating the bleeding obvious 