I get lots of questions with regards to colouring with Prismacolour pencils and thought this information may help you. I am no expert as I have only been colouring with my Prisma's for about 8 weeks (article written 28/04/08) but hope this may answer some of your questions.
I use Prismacolour Premier Pencils as these are the highest pigmented pencil Prisma sell. Sansodor is a low odour solvent. The make I buy is Winsor and Newton and I get it from Hobby Craft for about £3.50 a bottle.
You can also buy the paper stumps there which look like pencils and are compressed paper (You may also here people call them tortillions). The ones I use are double ended. They are about £1.50 each in hobby craft but your local art store will sell them much cheaper. Mine sell them for £1.25 for 3. There are different qualities of paper stumps and am afraid it will be trial and error until you find the ones you like..The colouring part is just so simple but can be time consuming as I do like to make sure all the lines are blended well - that's the perfectionist part of me!
I bought my set of 120 Premium Prismascolor pencils from Ebay. They came from the US and took about 10 days to arrive. Always ask the seller if they can mark the package low to avoid customs - though some will not. When I need to buy them individually I buy them from 1buy1pencils.
With the prisma's you just put the colour around the outside of the object, so say for example a dress. You can put a little more under the arms as this is where the natural shadow would occur. You dip the paper stump in the sansodor and pull the colour inwards in circular movements. This gives a great effect leaving the inside paler. Be sure to go over the outline with your stump in circular movements to get rid of any pencil lines. Go easy on the sansodor and be sure it has soaked well into the stump before putting to paper. Sometimes I dab it on a bit of scrap first. You can then pick a darker shade if you wish to add more shading but I find I can shade very well just using the one colour. When you have used the paper stump leave to dry then just file the end with sandpaper or an emery board and then you can use again for another colour.
The best paper I have found (you will think this is strange but I got this top tip from a friend AngelJakki) is Concord Plain Record Cards (pack of 100). This card is just great and blends a treat. It is also so cheap as I was buying Artist pads for about £6 ago. Here is where I buy mine. I know the delivery is a pain but if you order about 6 packs it will only come to just over £10 with delivery. You may be able to get them in Staples (£2.09 per pack) but I know they are fazing them out and using their own brand which aren't as good (only my opinion).
Update - October '08: I now use Momento Tuxedo Black ink. This is such a super ink and the only one I will use now. I warn you though as it's hard to get hold of. It works a treat with Prisma and Copics/ProMarkers... also so perfect for using when you might want to combine mediums. Another great thing is that you can easily wipe the ink off with a damp cloth as I would need Stazon remover with the Memories. So saving pennies too! You can find this ink over in my store.
Update - Febuary '09
I was asked recently what colours I recommend. These are my personal favourites but hope this helps if you are just starting out.
Skin – PC928 Blush pink
Cheeks – PC929 Pink or for a rosier glow PC925 Crimson lake
Wood, earth or to give a distressed or dirty look - PC1082 Chocolate with PC946 Dark Brown for shading
Jean clothing – PC901 Indigo Blue
Blonde hair – PC1012 Jasmine with PC1034 Goldenrod for Shading
Brunette’s – PC945 Sienna Brown and/or PC943 Burnt Ochre – PC946 Dark Brown for shading
Red heads – PC944 – Terra Cotta and PC946 Dark Brown for shading
Metal – PC949 Metallic Silver
Sky – PC1086 Sky Blue Light
Grass, leaves – colour used dependent on matching with dp - PC1005 Limepeel, PC988 Marine Green, PC911 Olive Green, PC1090 Kelp Green, PC908 Dark Green
My favourite colours – PC994 Process Red, PC925 Crimson lake (used lots at Christmas) , PC992 Light Aqua and PC905 Aquamarine
If you have any great Prisma tips to share or any questions.. please do email me and I will update this post.