Other cartoonists may have different ways of going about strip development, so keep that in mind as I offer my method.
I prepare a number of sketches of the characters with differing facial expressions. I also like to use tracing paper (or wax paper) to overlay on drawings to change expressions.
Finally, I put the sketches in a panel approximately 13 1/2 by 4 3/8 inches. I try to consistently fit all my dailies into the same format. I do it large so when it is reduced after inking it looks sharper.
I then ink the strip (at least until I am able to do it with my Wacom Tablet), scan it, and then add the type and logo.