Each fur is different and challenging to sew. Remember that there is a grain, or direction that the fur lays. I've forgot several times and cut a piece where the fur was going to look upside down and then didn't have enough fabric left to fix it. You may have to use extra yardage depending on the pattern and the grain. It really adds to a costume, like for a tiger, if you line up the stripes rather than just cutting randomly. Use pins. It can really shift and stretch. Where multiple edges meet, hand sewing may be necessary. Use upholstery thread since you're going for heavy use. After your finished, use a stick or comb to fluff out the seams so they don't show as bad. If you are going to really wear it longer than a trick or treat outing, a lining is going to be more comfortable than a leotard. You don't have to seal the seams to stop fraying but you may find covering the seams with bias or lace is more comfortable. I've worked on a few mascot costumes where comfort and movement matter as much as looks. It is hard on sewing machines so take your time and your project will look all that better.
