Well I'm not sure what you use, but I draw using an .05 lead pencil with colored lead along with the standard. Other than that, when I shade I focus on making the outlines for the shading practically invisible (or I don't use outlines at all and wing it lol) by matching the shaded part with the darkness of the outline. If because of this the rest of your drawing looks too light, either work on making your outlines lighter or redraw over the lines your your drawing is darker and more equal.
EDIT: unless of course it is a part that you do want contrast like hair and stuff to tell where the outline is. Although you do want to keep a color balance for hair, it is in most cases better to darken the hair around the outlines (at least that's what I mostly do). Also sorry for this extremely wordy... Explanation? Technique? Whatever you call it lol. (I can probably write a fairly large essay on shading if I needed to but that's the basics that I follow)
I can't give you any tips, just keep drawing~ your initiative will tell you what to do~
inb4, try searching for flight time, since that rule happens at everything, even drawing. the more hours you spend on something, the more better you'll be at it