To hem the leg openings I did the lettuce hem edge. I did two rows of shirring about 1.5 inch above the hem. You could also sew on an elastic if you like.
I also took the short cut while finishing up the top of these bloomers, I just sew on a waistband elastic with the zig-zag stitch. My rule of thumb is to take the elastic 3 inches lesser than the waist measurement. Then I join both ends together, and then sew it over the bloomers with an even stretch. I pin the elastic at every quarter of the waist of bloomer so it is evenly stretched.
And that is all.