Look no cracks! Great pastry, gluten-free
Wheat flour is actually really bad at making shortcrust pastry. I know you might be surprised to hear this, but wheat flour is very good for stretchy textures or super thin ones (think bread or filo pastry) thanks to the natural elasticity of gluten, but not for light, melt-in-the mouth ones. To make really good shortcrust wheat pastry you have to be careful to keep it cool, or it will become chewy and shrink like crazy in the oven. That's why there are all those instructions about iced water and marble surfaces etc.
Ok, so this is where gluten-free pastry has a head start. You won't get the shrinkage problem or the chewiness. There can be a problem with the pastry falling apart, crumbliness and dryness. After a lot of experimentation, I realised you need more water than you'd expect (rice flour, the base of most GF flour blends) absorbs moisture slower than wheat flour) and just the merest hint of xanthan gum (or your pastry will become too hard or have a 'squeaky' texture).
The pastry in my book, Gloriously Gluten Free, took ages to get right but I swear you'd no-one can tell the difference (apart from the fact it holds its shape so beautifully!). Here it is rolled - no cracks!
To get the best results, my flour blend is a must because that is what the recipe was based on. But if you don't have time, Doves Farm plain flour blend works well. Don't use a flour blend containing xanthan gum or other additives - I find it's too difficult to get the texture you need.