okay! so, i hate the computer, so i am consigned to colour by hand. pencils are okay, but paint makes more impact. alas, i have no paint. so I've tried playing with pastels, they're very VERY messy things though
there's a thing that's very useful with keeping pastels: spray fix glue. you spray it onto your piece and voila, now pastel won't get everywhere and/or smear if you accidentally brush it. it comes in a can that looks like spray paint, and i've found it at most arts and crafts stores.
i don't do pastels that often, but i always find that smudging things = <3. yours look very nice :)
Use hairspray. It's what I use. Unlike some fixiative it's permanent. However it's usually pretty readilly available. Just hold the can 2-3 feet away from the picture and apply a verry light coat. Viualla! No more smudges!
Now, as for your drawings you could do more to bring outsude colors into the main figgure. look at this random pic:
Notice that the shadows are not just darker shades of the cat's color but rather the blue from the back and foreground. This happend in real life as well. Look carefully. Quite often your own shaddows are more blueish or redish than just brown. And that's one of the neat things about pastells that I think you missed. It's a pain to do I know. But the effect can realy be quite beautifful. I'd like to see you do more like this.
Help me live my childhood dream of becoming the head of an evil corrupt corporate conglomorate: