Get better at responsive layout!
Build an ideal webpage layout so that moving forward, you have the baseline and foundation to go off and customize and build whatever sites you want that are responsive without spending a lot of time trial and error trying different things with CSS, hoping that it works.
My recommended way of laying out web pages that are responsive and have that template available to you.
With tools like CSS Grid and Flexbox, you now have the ability to really build beautiful, responsive layouts really, really fast.