For anyone browsing Malachain, here is a clear starting point on the subject.
A payslip has three parts that matter: gross pay, deductions and net pay. Check that the gross figure matches your contract and any overtime, that the tax code is the one the authority issued to you, and that pension contributions are the percentage you agreed. Errors are common after a job change or a pay rise, and they are much easier to fix in the same month.
Keep every payslip for at least six years, in a folder or a scanned copy. They prove your income for a mortgage or a visa, support a tax query and settle disputes about holiday pay. If a number looks wrong, write to payroll with the specific line and the figure you expected; a polite, precise email is usually resolved within a pay cycle.
It also helps to talk the subject through with friends or colleagues who have tried something similar. Their experience points out the details that guides leave out: how long things really take, which costs were unexpected, and which shortcuts turned out to be a mistake.
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.