Mincemeat often requires an overnight soak in the alcohol, often brandy, to plump up the dried fruit. Some recipes require a cooking stage, to heat the mincemeat through and help to seal the jars. Others simply use the mincemeat within a few weeks. Mincemeat is often made on Stir-up Sunday, the last Sunday before advent.
Mincemeat does not require suet, you can use frozen grated butter or a fruit puree to help make them juicy. Suet tends to have a flour coating, so butter is a good substitution if you need to make your mincemeat gluten-free. Mincemeat does not require alcohol either, and you can substitue orange juice in its stead.
If you want to give a little life to some shop bought mincemeat, try adding a little grated orange zest, some chopped marzipan or a few nuts to the mixture. A little extra brandy, kirsch or rum would also work well.