Unless a recipe says otherwise, always use butter and eggs at room temperature for baking. The main exception is pastry as this normally needs cold butter, but otherwise room temperature is best.

If possible, use digital scales for measuring ingredients when you bake. With baking you normally need to be a bit more exact with measurements compared to other home cooking, so this will help you get a better end result.

Use a small piece of dough rather than your fingers to press your tart shell into the edges of the tin to prevent it cracking. But if it does crack don’t panic! Just use another small scrap of pastry to fill the crack and brush a little water over it to keep it in place.

To avoid the dreaded soggy bottom of a quiche or tart, brush the inside of pastry case with egg after you’ve blind baked it (i.e. baked it in the oven before you’ve added the filling). This will seal the case and stop your liquid filling seeping into it.

Sometimes a pastry case can pull it away from the sides of your baking tin (“shrinkage”). There are 2 ways to avoid this:
1. Pop your case into the freezer for 5 minutes before you first put it in the oven to blind bake. The shot of cold will stop it shrinking.
2. When you drape your pastry over the tin, leave it to hang over the edges. Don’t trim until after you’ve baked it.

If you leave your dough to ‘relax’ in the fridge for at least 30 minutes before rolling it out, it’s less likely to shrink too much, but I tend to find it’s best to do one of the above too.

Always used aged egg whites to get the best results when making macarons. 3 days before you make your macarons, put egg whites in a bowl in the fridge, cover with cling film and poke a few holes in the film to release the liquid.

Powdered colours work best for colouring macaron shells. Liquid colouring can result in your shells being too soft.

You can freeze macarons for up to 3 months (either shells or whole!). Leave them to defrost for about an hour to room temperature before serving.

Source: Ganache Macaron
It’s best not to store chocolate in the fridge; refrigeration can make chocolate develop a white coating and also destroy the flavour (plus it can absorb the flavour of anything a bit smelly in your fridge). It’s best to store chocolate in a cool, dark place so a cupboard is normally fine.

If you’re melting chocolate and it seizes (i.e. it darkens / thickens or gets a bit grainy), just add a dessert spoon of hot water and mix it back into the chocolate. This will work if you’re using the chocolate for baking or ganache, but not if you’re tempering it to make chocolate shells or bars.

“If you’re making a mousse or a tart, the more money you spend on the chocolate the better it will taste because you’re not baking out the flavour.” Source: Jennifer Earle, Chocolate Ecstasy Tours