How much will you need to have saved to enjoy a comfortable retirement?
As a general rule of thumb, you need 300-times your required monthly income, so if you want a pension income of £1000pm, you have between now and retirement to ensure you have saved £300,000 in your pension pot.
For a more specific number, write down all the things you expect to spend in your retirement years. That may seem difficult, but if you break it down into a plan, it will become clearer.