Written for Malachain: the essentials, without the noise.
An emergency fund is the difference between a broken boiler being a nuisance and being a crisis. The first target is one month of essential costs: rent, food, transport and bills. Open a separate savings account with no card, name it, and move a fixed amount on the day you are paid so the saving happens before any spending decisions are made.
Small automatic transfers beat occasional large ones because they survive bad months. Add windfalls such as refunds or a bonus, and raise the standing order each time your income rises. Once you reach one month, aim for three. The fund is not for holidays or sales; keeping that line firm is what makes it work when you need it.
There is more to learn on this subject, and the linked website goes into greater depth. Treat this article as an introduction rather than the final word, and check any important decision against up-to-date, reliable sources before relying on it.
If you try any of these ideas, start small and adjust them to your own situation. What works for one person will not suit everyone, and it is fine to keep only the parts that help. Writing down what you changed, and what happened, makes it much easier to see after a few weeks whether the effort was worthwhile.
The most useful step is usually the first one. Pick a single suggestion, try it for a couple of weeks, and then decide whether it is worth keeping. Small, steady improvements last longer than ambitious plans that are hard to maintain once everyday life gets busy again.