(This is not money advice. This is just me trying to educate myself on this subject.)

Contrebuting into your pension.

It is thought that thinking about how much money you should contribute into your pension. You should Half your age This number (as a percentage) is how much of your monthly salary before tax you should into your pension every month.

For example, for a 30 year old erning £1000 (each month). Will half their age so 15 then it will be 15% of 1000 so their pension contribution will be £150. Then your contributions go up as you get older.

https://www.gov.uk/check-state-pension