Always rotate your fields to keep them as clean as possible
use flax bedding in your boxes
use big boxes...the bigger they are & cleaner they are, the faster a horse can accumulate energy
make sure to have enough employees to do what is required in your EC.
For example so I have 250 boxes...I have to make sure to keep at least 9 rising instructors, vets, make sure I have a saddler and blacksmith and 1 groom per 20 horses
Anyone think of anything to add?

When you first start out, first buy a greenhouse and the largest box ever depending on if you can afford it (box prices soar!)
And start planting turnips or wheat oat.

1-When you first start out i suggest only buying meadows and get some crops started right away as that is the only way to make any decent money in your EC.
2-Start your comps right away to make them get high prestige fast(comps bring up your prestige really fast)
3-To start them enter a low skilled horse in your comp(must find the comp first though)Then make the skill level really high(high as possible and put it to all breeds with the low skilled horse still in it.) That makes it possible to see and then your comps fills and runs!
4-Try hard to buy only 18m2 boxes it makes your prestige much higher.(use flax bedding)
5-Try to always keep the meadows clean and fertile.(or the horses get sick that are at the EC.
6-Health mashes and carrots are a go attraction for your EC.
7- Keep your EC fully staffed or the prestige and amount of boarders goes wayy down.
Thank You