If pastry making scares you then crumble is the place to start. It involves the beginnings of making a shortcrust pastry without the terror of making a dough. You get to practice crumbling the fat and flour together without being too concerned about whether you're being too hamfisted.
All your ingredients should be cold, the fat should be cut into diced pieces and rubbing the fat and flour together involves just the tips of your fingers. You shouldn't ever be squeezing or squishing the fat and flour together.
I prefer to use self raising flour in my crumble topping and if I don't have any will stir in a teaspoon of baking powder. I have no explanation as to why I do this, I just do. Plain flour would be fine.
For my fruit base I just use whatever I have to hand: apples, pears, frozen fruits (defrosted) etc. Just put them in your dish and sprinkle enough sugar on them so your lips don't pucker.
200g flour (self raising or plain)
125g margarine (good quality, good tasting)
60g caster sugar
Rub the flour and maragrine together until it looks like rough breadcrumbs then stir in the sugar.
Topping: replace some of the flour with ground almonds or any other type of crushed nut (pecan or hazelnut spring to mind).
Can also be used for: sprinkling on/covering top of cakes and cupcakes.
Freeze? Yes. The crumble topping can be kept in bags/containers in the freezer)