Sculpting with milliput?

ok thanks guys - I use the normal on ewould you recomend to use superfine white ?

Just be careful with the amount of water... I use the superfine one and it tends to become quite tacky/runny if it is too wet.
When I need more rounded/smooth details, I don't do them immediately after mixing, I do a raw sculpt, let it sit for a couple of minutes and then end up the details with wet tools; this is for the reason mentioned before.
Smooth any fingerprints with water and even your same fingers.
When cured, be sure to sand it well with fine sand paper.

I use milliput, you mix it in equal parts, sculpt and let it cure for about 4 hours. You have about half hour working time with it before it starts to cure. Make sure your tools are wet while you're working and it can be easily smoothed with a wet tool or finger.

I can't really give you much more info without knowing what the issues you're having are.