When I fell in love with Fimo back in '82, I had a sheet of tempered glass (probably left over from a previous project), a round skewer (sometimes just a toothpick), a razor blade, scraps of sand paper and some clay. There were no books but I learned from some of the ladies at the miniature club I had joined. I also had some left over ceramic tiles, some broken, some very small on which I sculpted tiny items for doll houses and 1/12th scale room boxes.
For seven years I made 1/12th scale miniatures, did little local shows and when I sold something (after jumping around doing the happy dance) promptly started making another one, be it a tiny doll, sleeping baby, tiny frame, tiny decoration, tiny wall hanging, etc. The more I made, the better I got. And, because first my friends and then folks at the little shows bought stuff, I was encouraged to make more. and more... and even more.
Some things that I have learned...
First, do what you love. I loved teddy bears, cute things, Victorian things and people. Over the years one's fingers will learn what's needed to be done to make what you see in your mind's eye.
Some of my tricks:
Always work on a tile not very much bigger than the bottom of what you are making. If making a tiny doll house scale teddy bear the clay body and legs might be seated on a piece of broken tile that was .75" across at the widest point. (To make broken ceramic or porcelain tiles safe to use, sand the broken edges until smooth.) It is much easier to use the point of a tool if there is very little baking surface under it.
If you need to lift your work, slide a razor blade or tissue blade under it to lift. This will avoid distortion.
Need something to do....? I used wire, brass sheets and other things to fabricate tools for... Textures, marks, 'stitches', etc. Poke your clay with lots of things, pens, scouring pad, sand paper, ball of yarn, anything, you might be so surprised to see what lovely patterns are created using simple items.
Most importantly, don't worry about any required tools, there aren't any, just have fun.