If you are having trouble removing soap from your molds, there are sprays you can purchase that will help with this. By spraying the mold before you pour your soap in, this makes it much easier to release.
Another trick I found was to place the mold in the freezer for up to 30 minutes and this also helps remove the soap if you are having trouble.
Making your own soap is a lot of fun, and most people really enjoy receiving these as gifts. Depending on how you process your soap, there are also wood soap molds, but I have never used these.
I have used both plastic and silicone molds and like using the silicone molds better than the plastic ones.
Once in awhile I find some good deals on these at the dollar stores or even the front section of Target stores will also have seasonal silicone molds. They will last a long time for several uses and you really feel like you get your moneys worth out of them.
Last Christmas I found some Christmas trees, snowflakes, candy canes and Gingerbread men and women that were so fun to make homemade soap for Christmas presents with.