Take advantage of the pension carry forward rules in order to benefit from any unused allowances from the previous three tax years. This is generally the difference between the old £50,000 annual pension allowance and your pension input that year and can be added to your relief for 2015/16. Note that the annual pension allowance is £40,000 for 2015/16 and 2016/17, although those individuals with income over £150,000 will have their annual pension allowance reduced by £1 for every £2 over £150,000.
To avoid losing pension relief brought forward from 2012/13 which lapses 5 April 2016, consider making an additional pension payment before 5 April 2016. If your pension input was £24,000 in 2012/13 then there is £26,000 unused relief available to add to your 2015/16 allowance. You would need to make gross pension contributions of at least £66,000 (£40,000 plus £26,000) to avoid losing this generous relief.