First of all, a good trick is to "secure" the farmer on one spot to accelerate their actions (Basic trick).
Do not waste your money on nothing else than 100 coins hay bales. They are like XP steroids! Oh, and make sure you leave some space on the ground for the hay bales.
100,000 coins gives you 1,000 hay bales @ 5xp each. What generates 5,000 XP points! Compares this to a 100,000 coins building that gives you only 1,000 XP…
So 1.000.000 coins will give you 50,000 XP! This is enough for levelling up, depending on where you are now.
I recommend Peas planted on a section of 20 x 17 (340) will give you 59,840 coins per harvest. This includes plowing and planting costs. With a security margin of 3 days you’ll win around 6,360 XP! Certify you save money for seeds.
The only negative thing is when you have to sell the bales of hay to free space for the next shift, which is not fun … But see the positive side of it, each "straw" gives you 5 coins in exchange!
In any case, do not purchase guides wish provide "hacks", codes and bots. They only bring the risk of losing the Facebook user account, or being banned from Farmville. There are tricks and tips that aren’t anything but improved techniques which achieve notable results. If you want to know more, visit the Farmville Secrets.