We have saved what we could over the years. As soon as we were in a position to we saved about £50 per month for both DCs which was boosted by a few thousand from a grandparent. This increased a bit as we got pay rises.
We invested in 5 year bonds at one point and then at 17 moved the money into savings in their names but they don't know the account details. They both know there is money in accounts for them but not how much.
For eldest (21) we have opened a LISA which has had 2 years of max money (plus gov contribution). This is sitting at almost £30k across savings and LISA (nominally for house deposit). Youngest will have broadly the same at the same age.
We have been thinking about how to continue saving for them as long as we can - currently in a very lucky position of our mortgage being paid off and being able to save about £300 per month each for them both. I like the idea of a SIPP but worry about the fees (as we have literally no idea about investments so would not be self-managing) - will have a look at Martin Lewis. I think for this we'd have to put money into their accounts as I don't think third parties can pay into an adult's SIPP (but happy to be corrected).
What I want is for them to have the option of perhaps retiring at 60 if they want so want there to be enough money for say 8 years of a reasonable amount before state/their own occupational/private pensions kick in.
We have some separate savings that we can help with deposits too. DH will get a very nice lump sum at retirement in a couple of years so we will be comfortable in our own retirement even with the money we have/are saving.
To be honest I thought we were doing really well but some of the amounts on this thread are insane.