Last season I didn't do any FTP testing. I based my wattage numbers on the results of my 40k TT in Arkansas. Not smart but gave me a good baseline to work from. This year I've decided to test more often to see my actual progress. So far so good. Test in January was right at my old FTP so started back at where I was at mid summer. Test this week was a big improvement. Probably where I was at mid cross season.
I started out too hard in the January test which I did on my cx bike on the trainer. February's test was on the TT bike on the trainer. I think for now I'll retest once a month. Come this summer maybe every two or three weeks as I get closer to State TT. I'm also going to play around with several different testing methods to see how close the results are.