Eyebrows varied from era to era so once you settle on what shape is best for your facial features, really the best way to shape your own brows at home is to use a stencil. You will use a dark brow pencil to fill in the shape of your would-be-brows and pluck any strays outside of those lines. Much better than free hand (trust me, I learned the hard way and it took a couple of years for my brows to recover!) and once you have your shape down, routine maintenance on strays should be a breeze. Since you said 30s is more your "thing" and that you have naturally thick and full brows, you may not even need pencil after shaping...just use a smudge of vaseline (very 20s/30s!) or clear mascara to hold unruly hairs in place and go!
I also think this is by far the best vintage brow tutorial I've seen...scans from a vintage magazine.
http://beautyisathingofthepast.blogs...rch/label/Eyes