You need professional help from a solicitor NOT a will writer [pause for all the ex-bus drivers and the like who have passed the simple test on writing wills, to complain that they are as good as any probate lawyer because they are will writers].
There's a bit more to it than meets the eye. How old are the children who will inherit? If under 18, they have to have what they are due to receive held in trust until they are. They needn't get it then; my own will specified 30 years of age before my daughter inherited the share, because, at the time, she was only 12 and I didn't know whether she'd be responsible at 18 or, indeed, 21 or 25. She is now 26 and responsible, so my latest will has not got that provision.
What provision is made for survivorship ? Whatever age they are, it is normal to think of what happens if one dies before you do. Remember, the person whose will it is "speaks from their armchair at death", and death may be many years after the will is written. A lot can happen in that time. Suppose one dies before you but leaves a child. Is that child, as yet unborn today, to inherit the parent's share? If so, that should be stated, and provision made for a trust to be made should they be under age, again with a provision for them to receive at some later age than 18, if thought desirable. The trustees are the executors of your will, in the first instance, automatically.
It is normal to provide that any gift under the will is of no effect unless the recipient survives the deceased by 28 days. And it is normal to exclude certain provisions of the Trustee Act 1925.
All such matters, and others, are simple for a probate solicitor, but not for you, unless you are one ! Even then, that person would have another lawyer draft the will ; you can't be too careful!