Hmm, you really need to give some idea of the value of your estate. If you're married or in a civil partnership then you and your spouse have a joint threshold of £650k, assuming that you give everything to one another. When the first of you dies, their personal allowance of £325k passes to the survivor, so IHT only becomes payable on the second death, at 40% of everything over the £650k (today's figures, of course).
Any death in service benefits, life insurance and pensions will usually not be subject to IHT as they're held in separate trusts already and don't fall into your estate.
The thing about IHT is that unless you have a very sizeable estate, putting a large chunk of it into a trust takes it outside your control (usually, depends on the trust), and you may regret it if you run out of money later in life.
For most people, giving part of their estate away by way of Potentially Exempt Transfers, usually later in life when they may have downsized and are sitting on a large chunk of cash, is a better option than tying their money into trusts and therefore taking away flexibility. So long as you live for 7 years after the date of the gifts(s), no tax is payable on them and if you die within the 7 years, IHT applies on a sliding scale.
I'm a qualified lawyer and will writer and have a paid for advert over on MN Classifieds (Small Business) titled "5* Will Writing Service Recommended by Mumsnetters" if you're interested.