I will have a small pension from previous job.
Plus I am buying in NI years (voluntary contribs, not currently working). These are very cheap for what you get back.
And I have a small personal pension going. This was especially attractive because for me as a low earner the govt. adds in money I didn't even have to earn!
We have paid off our debts and mortgage already, we have "enough" in cash savings and do occasional investments in unit trusts.
We already have so much of our wealth tied up in our house, I wouldn't want all our pension dependent on one type of investment (property), so personally wouldn't choose Buy-to-Let as a pension scheme.
And otherwise I will work until I'm 75, and rely on DH's pension (company sponsored, but not a final salary scheme) where I have to. Willingness to work until 75 was the biggest factor in all the scenarios I tried to work thru on a spreadsheet.
Over the age of 65 the tax-free allowance on income goes up (goes up again after 75). Assuming all conditions continue the same until I retire, and that I live as long as I expect to, I should get a bit more income from the personal pension than I will from DIY pension planning (e.g., in the shares ISA). But the shares ISA income will be tax-free, and the various pensions/NI income will be low enough to attract little tax.
It's really complicated planning all this, I don't know if my strategy is best, I think I can live with it, though.