I tend to do longer endurance type races, not the shorter xc stuff.
For carbo loading, in the 2 days leading up to a big race I will have a big pasta meal and another meal with lots of carbs (like rice or potatoes). Also will eat some porridge or more cereal than usual for brekkie.
On the race day morning, I’ll have porridge, or cereal plus some beans on toast (no butter). If it’s a long race, I might have some meat, like trimmed bacon, for the protein content.
Normally, I just try to eat a well balanced diet, not too many fats or sweets, and not too many carbs either. have lost a fair bit of weight recently by doing this and doing lots of cycling. Plus have got a lot faster on the bike.