Start by mapping out minimum 'subsistence' living expenses and 'leisure' expenses – from today, every year and into later life.
e.g. you may wish to spend more in early retirement compared to later retirement e.g. you may wish to downsize your expense requirements say from age 70 or 75?
Pensions – allow for state pensions, indexation of annuities, defined benefit pensions and state pensions.
For personal pensions and flexible drawdown – suggest you allow for two scenarios – no growth and 4% pa net growth.
Plan to protect from market volatility as you get nearer and into retirement with different risk profiles for – short term (0-5 year money), medium term (5-10 year money) and long term (10 year + money).