Ahhh, now this is what I was looking for:
Just choose one... say, you Wednesday ride. Tell yourself something like... "Every Wednesday, during my ride I will ride as hard as I can in the biggest gear I can for 2 minutes, then I will rest and then I will do it one more time."
That's all... after a couple of Wednesdays you will do your two intervals and think - "Hey, I still feel fine, I'll do another one or two..." Voilah... without realising it you will have baby-stepped yourself into a cruise interval training ride.

Or maybe Wednesday doesn't work for you, and you don't want to work on surging and keeping up with the group. You get dropped on hills. And, hello, on Tuesdays you happen to have a steady climb in the route you normally ride that day. OK... ride as per normal, but when you get to the top, turn around, go to the bottom of the hill and climb it a second time. Try and do the second climb as quickly as you did the first - or more quickly!
Voilah again... in a few weeks Tuesdays has become a specific hill rep day to make you stronger, give you more endurance and ensure you are less likely to get left behind on hills...
Things I can do without having to monitor heart rate or stay in a particular zone. I think I can do these.

Spazz - you made me cry with the suggestion that I may be at my performance high.

RR - wow, that is one journal! I do list some of the stuff you mentioned; like who I rode with, what route, etc.

I ride about twice a week with the 2000 UCI Masters World Champion and 2003 NORBA National Champion. Yep, rainbow on his sleeve and all!!! This man is amazing! His wife is pretty good on a bike too. I've seen him put the hurt on guys half is age!!! So, I'm honored to ride with him and he motivates me to try to improve. But it's just too easy to just take it easy on my solo rides. I have some things I think I can try that will make it fun. Thank you.