It will come as no surprise if I tell you I am not much of a sculptor...
However, part of our hobby involves using putty at one stage or the other (unless you're a plastic-only kind of modellist) to simply fill gaps, repair damaged detailsor even add new ones for conversions.
In all those circumstances, you have to learn by trying. learning from other people's experience though is allowing shortcuts though.
Though many painting techniques are covered in magasines and all, I've always felt that you don't get much sculpting tips or tricks and that basic techniques aren't as well known as they are for painting.
The aim of this post is is no way to tell anyone what to use as I'm clearly out of my jurisdiction here but it's aimed to share with you what I use and learn from your tips and advice, critics and comments.
The tool below is the first sculpting tool I got when I started pushing putty back in 2000. You can see it's not the most precise of tools. I think when I got it it had already been used for dentistry or something has it was clearly not brand new. It did what it had though and I quickly switched from Milliput to Green Stuff (I won't go too far on the subject of putties as it clearly exceeds my very limited knowledge of the only 2 I use).