Have a plan
You must have a plan. You must know why you are going to that race. Maybe it is for training so that you will be in peak condition for your main goal weeks later, or maybe you are going to get placed in the top 6 or maybe you are going to win, but you must know why you are going.
Using a race as training
If you are going to a race that you are viewing as a training event that will increase your fitness and abilities so that you will be in peak condition for an event later in the season there is only one way to ride the race. Attack, Attack, Attack. Each time you attack and get caught it will make you stronger. You might end up getting dropped but that is OK. You will eventually attack someday...
Races are not won on Strava
Fitzy also had strong opinions on people racing who gauge their ability on where they rank on a Strava KOM leaderboard. This gives very little indication of how they will do in a race. All that matters in a race are how many people, if any, cross the finish line ahead of you. Keep some of your spins off of Strava. Maybe only upload them in batches of 10 or 15 every few weeks...
Use others lack of planning to your advantage
In a race of 100 riders there are about 80 who are there to see what might happen and maybe they might get up for a place at the finish. That is fine and they enjoy that, but if you are being competitive you can forget about that 80%. Then there are about 15 who are seriously planning on getting a placing in the top 6. Be at the very least one that 15 and try to figure out as many of the remaining 14 as possible to know who to follow approaching the finish...
Train in bad conditions to race in bad conditions
You do not necessarily have to like training or racing in the rain but you must get used to it in order to shorten your odds of a victory. On a wet day at least 50% of your opposition will have cracked before they get out of the car. Once you have trained in bad conditions you can use this to your advantage.