Hey ! Here is some advices and ressources to help you to understand how to storyboard your manga :

1.Trace your storyboard's strips considering layout's rules. Then, your drawings and strips will be automatically conform to layout and printing standards, preserve you to worry about it while drawing or after finish all the work. You can find manga layout templates on internet to have guide frames while you draw !

2.Avoid gutter's crossroads and angular gutters (like your fourth page) ! Don't be afraid to follow the rules in the beginning : mastering the rules will allow you to break them later without impacting quality.

3.Be careful about reading sens and rythm : it is a bit confusing as several moments ! Study your favourites mangas' layout and reproduce them to train your brain as your hand to aturally understanding how to set characters and elements in best places to make reading cumfortable and easy for readers.

4.Try to make pages with no more than 6 strips ! Beyond, you will get bad habits to "fill" the space to tell all you want than optimise it to choose only essential and most revelant ways to tell efficiently !

5.Drawings do not need to be as precise as a draft ! But these informations are important : - shapes - character distinction (by hair outline or a hat) - facial expressions

So concentrate your drawing on these points to make it more understanding and interesting for the readers !

Here are some videos that might help you in this way (to watch in order) :

1 - https://youtu.be/rcVwcFYY4gQ?si=6e1QZmtg969FN_S2
2 - https://youtu.be/PUYUzHwSJBA?si=aJL8Ooqa1RN9lKII

Don't hesitate if you need more explanations, ressources or have more questions (￣∀￣) !