Yes, DH and I have. Our previous ones we had help with from Age Concern (as it was then). We re-did them more recently, being very careful that the wording wasn't ambiguous.
Fortunately, they're very simple - everything to each other, and if one has predeceased the other, everything to DS. If they were more complicated we'd probably ask for advice.
If you are a married couple leaving everything to each other is a good straightforward will. Then the surviving partner will have no tax to pay and can decide a new will later.
More complex wills involving property and several beneficiaries need more care, you should take legal advice
My DM left a DIY will, half of her estate went to someone that she didn’t want to have anything, she left a letter as back up, signed and witnessed to make sure that her wishes would be honoured. It was thrown out when it went to probate and the beneficiaries that she wanted to have the money got nothing. The wording on the DIY will wasn’t valid, and the letter made it worse.
Yes, you're right, M0nica - but I did say that our wills are very straightforward and that we were careful about the wording. Since only ourselves and DS are involved, there shouldn't be a problem - there's no-one else with an interest. We have considered making more complex ones and would most certainly take proper advice for them. Anything more than absolutely basic needs legal advice.