Well bursting is a priciple of getting a lot of exp fast, you can get between 4000-9000(for fires) depending on what team you're in. The best thing is to start with horses that are lvl 1, when a horse reaches lvl 10 it will be too old and will give way less exp. Make sure your spd is the same as the horse at the beginning(so around 52 is best, don't change your spd). Then the best thing is to get yourself the goddess skill for real bursting. Then for fire the sequence will be: slow down(enemy)-poison(enemy)-Hot fire(on yourself)- Hagendis hit(enemy). if you don't have hagendis hit yet then use your highest other skill, but becareful not to use an skill that atks multiple enemies.
When you're in a full team then the exp will be higher then when you do it alone or with 2 or 3. You can do this with electron remote or without. But you have to look closely when you do it manually.
So you fight till your Horse is lvl 9-10 then get a new one and start over again, you'll see you'll lvl way faster. If you're a different element, you can see in the guides mentioned above what the best sequence is for you^^
I hope it helped a bit^^