It doesn't matter, it's strictly your choice but for some advice, composition and decomposition are one the more useless skills....YET if your going to choose scroll making composition comes in GREAT handy. So if your going to chose scroll making, get the composition skill with it.
But the best 2 skills, in my opinion, are hp/spr/anidote making, and scroll making
because your realize, those two products are the products that you'll spend the most money on in the feature.