When making small individual tarts it is best to roll your pastry into a log (rather than a disc) before chilling and resting.

When you come to rolling out the pastry, cut the log into slices and then roll out each portion into a round before pressing into the tins. This no-fuss method means there is very little pastry offcuts and no need to re-roll scraps (which often causes the pastry to shrink when baking), ultimately giving you more even tart shell cases. 

It is sometimes hard to flatten a biscuit or pastry base of a slice. Fingertips often create an uneven surface and a roll pin is completely impractical once the mixture is in the tin. A straight-sided glass, however, is the perfect size and can be easily rolled over the surface to make it not only smooth but also very even.

When making pastry, such as a shortcrust, by hand make sure you only use your fingertips to rub the butter into the flour.

Avoid using the whole of your hands as the palm is the warmest part and can melt the butter which, in turn, may cause your finished pastry to be heavy and tough. Rub the butter chunks briefly between your fingertips, breaking it into smaller, flake-like pieces while coating with the flour rather than rubbing them together.

Also remember to keep the palms of your hands facing upwards, to help with the action of breaking up the butter chunks, and lift the mixture high out of the bowl as this will aerate the mixture and help give it a light texture when baked.

This is a great technique to keep in mind when making scones and pastry.  

When making a pie or tart there is no need to grease the tin before you line it with pastry – the high butter content in the pastry will naturally stop it from sticking to the tin.

If you grease your tin, the pastry is more likely to slip down the sides/shrink during baking leaving you with a tart case that with very short sides and not much room for your filling.