Getting started phase: was 15 min a day. Over-hyped phase: for some memory "projects" maybe 30 min a day. Now: I just use memory tricks all day long without really training. However every day, for the last 30 min of work I try to recall everything that was important that day (free recall). At the start of the workday I recall the top-3 things to work on.
How much time would you say you spent on training over the years? (Hours/week when you were building this up, or whatever)