All the tutorials I've come across for making troll horns seem to be American; and obviously all the brands are different here.
I would preferably like to use air dry clay instead of that oven bake stuff.

Has anyone here used any modelling clay that they have found to be decent? Any replies appreciated, thanks!

Btw, it would be Karkat's nubby little horns I'm making.

Jumping clay is brilliant. It's really feather light and air dries pretty quickly. It comes in a few basic colours but once it's dry takes most paints really well.

http://www.amazon.co.uk/Sculpey-Original-Polymer-Pounds-Pkg-White/dp/B0016N6CMU/ref=sr_1_2?ie=UTF8&qid=1352298723&sr=8-2

This stuff. I used it for Lucy/Elfen Lied horns.

EDIT - Nevermind, you want air bake clay...

I use Milliput for everything. It a two part epoxy clay. Don't buy it from hobbycraft though as there stupidly expensive - but you can get in plumbing places or ebay:
http://www.ebay.co.uk/sch/i.html?_sacat=0&_from=R40&_nkw=milliput&_sop=15

It is practically indestructable. I've used it for so many things now which I've stood on and dropped and never had any problems with it breaking. The only problem is that it's heavy but it's as heavy as any clay option so that is something to bare in mind.

Basically it comes as two tubes of clay and you cut of equal parts of each and mix. Once the colour is even mix it some more and then use it to mold into shape. Once your horns are made smooth any rough parts with water - milliput goes beautifully smooth when rubbed with water. Also unlike other airdrying clays it can be painted within 6 hours (i think that's what the instructions say) and then fully hardens within 24 hours. Also because it's not a water based clay I have never noticed any shrinkage with milliput. Some of the other air drying clays will shrink and crack.

Just make sure you wear gloves when you use it as it can cause local skin irritation but it's nothing to be scared of

Good luck

We tend to use Fimo Light for our troll horns at Blood/Sugar as Raine tried another air-drying clay and it was too heavy. It's easy to get ahold of in craft shops or on ebay. though you have to roll it on a flat surface (Zomboi's tip) to get it smooth.

The real trick isn't the type of clay as there's plenty of good light airdrying clays out there, as other people have already suggested(I've used Crayola Model Magic in the past for projects too though I prefer Fimo Light), but how you affix them. We poke holes in the bottom of the horns before they dry with the end of a perncil or paintbrush and then Zomboi carefully melts holes in wide plastic hairbands with a hot nail (I'm not trusted with fire) then lots of hotglue is applied to keep them securely on.