Mikka,
There are quite a few posts about blending garlic and/or ginger on the forum.
Personally, I use a basic mini blender and blend it (i.e. fresh ginger and/or garlic) in a little water.
I then freeze it in ice in an ice cube tray (1 tbsp or 1 tsp sizes) and transfer the cubes to a sandwich bag to store in the freezer.
I can't tell the difference between doing this from fresh (in the final curry)
Some people prefer to use oil rather than water.
To my mind, either works well (regarding blending) but I think using water lends itself better to subsequent freezing (IF that's what you intend?)
The bottled stuff is, at best, OK, but it has a definite taste of preservatives/stabilisers for my liking