Realistically, how difficult would it be to DIY new kitchen cupboard doors?

The cabinet doors and drawer fronts in our kitchen are about 50 years old and a range of different widths (none of them standard). We'd like to refresh them, because they're looking worse for wear. However, we've just bought the house and don't have budget to get bespoke doors.

How tricky would it be to make them ourselves? Any tips on what would be involved and what pitfalls to watch out for? Husband has decent skills with a saw and we've got garage space where we could work on this over the next few months.