So, you spend your summer putting in long hours of volume, your fall building up your intensity, and your winter tuning your technique. Now it's finally racing season, and when you get to the race site - hopefully it's at least the day before the race, so you have some time to prepare! - nothing you do will change your fitness level. Fortunately, fitness isn't all there is to having the best race you can.
Over years of prepping for all kinds of different races in all kinds of different conditions, everyone has developed different pre-race routines. While the same thing that works for one racer might not work for another, I'm going to try to list some things to think about doing at a race site the day before the race, to try to get as ready as possible.
1) Ski the course
This is very important! There's nothing good about being on your course for the first time on race day, and finding a hairpin corner or massive climb that takes you completely by surprise. Even if the course is on familiar trails, it's worthwhile to ski it to see what the grooming's like, if there are any bare patches (this year especially), and if the snow, and therefore the waxing, will be different in different sections of the course. If skiing the course is unrealistic, as for a 50k loppet like the Keski, think about picking some of the more technical portions to ski the day before; good choices for the Keski might be Burma, the Ridge Road section, or trail #15.
2) Visualize the course
Now that you've skied the course, think about those technical sections you've just run over, and how you'll be able to ski them fastest. Consider technique (offset vs one-skate or diagonal stride vs herringbone run), consider pacing, consider which lines to ski. If you feel unsure, take the time to ski over small sections more than once, to experiment and see what works best for you. You want to go to bed knowing how you plan on skiing tomorrow's race.
3) Inspect the start/finish and tricky intersections
They may seem obvious at the time, but after half an hour of hard racing, lap lanes and finish lanes can look very similar! Make sure you know where to go on each lap.
4) Do some intensity
This is where there is a lot of variability. Personally, I like to do some mid-duration zone 2 and then zone 3 sections, followed by some sprints. Veteran Wayne likes to do a longer continuous zone 4 interval. Either way, the idea is to get used to going fast again - especially if you've been travelling - and to get used to going fast on your course's terrain. It can be a good idea to do some of your intensity on those tricky areas you've been carefully checking out in your course inspection.
5) Eat plenty of good food, drink plenty of WATER, and get lots of sleep!
If you don't already have a pre-race routine, it's never too early to develop one. Try out some different ideas, and find out what works best for you. If you do have a pre-race routine, but you feel unsure about it, it can help to experiment and try different things - you might find a routine that works better. The one thing to remember is not to do something revolutionary for the first time the day before your important race. While it might work wonderfully, there's an equal chance it won't! Try things out at small races, and then when you get to the big one, you're ready to go.