o - Capital gains tax annual exemption for 2011/12
o - Annual Inheritance Tax exemption for gifts
o - Annual Individual Savings Account (ISA) investment limit.
In addition, the Annual Investment Allowance is decreasing from £100,000 to £25,000 from the 6 April 2012, thus if you are planning on buying plant and machinery in the near future; significant tax savings can be gained on purchases made prior to 6 April.
You may also wish to make additional pension contributions by the above date.