It is a tricky one.
I could easily blame health, lack of time or any one of a multitude of reasons but I still try and get out there every day, every single day come rain, shine, darkness or the wind.
Saying that, I've been busy at home in the garden for the last month or so, so whilst not out bicycling, as much, I've been doing a lot of physical grafting.
A few tips from me;
1, Set aside an hour every day as your exercise hour, make it part of your routine, no if's, no but's, it is time set aside.
2, Never feel compelled to put a herculean effort in every time you go out. Sometimes it is ok to just pootle up to the pub or coffee shop and spend half of the set aside hour in there, that golden hour is for both body and mind.
Some days for many reasons you are not going to make it out but if you have set aside that time, you mostly will. For me sometimes, especially say on a wet and windy November evening it is very difficult to get up out of the chair and go out but once I do, I'm always glad I did. I'm never going to be a speed or distance guru but I bet I'm out there more than most, however short and slow the rides I do are.