Stuff like training consistently, following a structure, planning the season, etc. are obvious. Three things stand out in 2019 for me:
1. Regular and sufficient quality sleep. What’s the point of putting a lot effort into training when you don’t allow time for rewards to come to fruitation.
2. Eat to fuel workouts. I now always keep a gel handy for 75-90 minute TR sessions, and it seems to help me finish workouts as intended.
3. The devil is in the details. Doing a race? Do the homework, check the route and profile. Slimming your bike or equipment? Analyze all components and pick the lowest hanging fruits. Looking to drop a kilo body weight? Review food intake both in regards to quality and quantity. Busy schedule coming up? Look for tiny pockets of time, there’s always a 30-45 min gap somewhere for a quick run at the very least.