Although Gold can be useful for different things, it is recommended that you save it to spend unlocking gates. This way you spare yourself from having to invest real money in order to keep progressing swiftly through the game. Acquire boosters and shovels and such through other means.
Later stages will require you to match three eggs in order to hatch a set number of chicks. However, it's all too easy to let the required eggs overrun the board. Focus on their positioning and try to make moves that keep the eggs mostly in one section of the field. That makes it easier to make critical matches and it leaves you with more of the room you need to match other sets with multipliers to improve your score.
For easy lives if you're close to running out, simply set the time on your device a few hours ahead and then open up Farm Heroes Saga to see that your supply of lives are replenished. Feel free to repeat this trick as many time as desired.
Avoid eliminating easy sets near the top of the screen as they arrive. Instead, watch for sets you can eliminate closer to the bottom. This raises the chance of coming across an especially lucky chain reaction near the top of the field, as new pieces arrive.
Flowers can prevent you from making some great matches, forcing you to work around them until you've eliminated the ones that are positioned most inconveniently. Instead of fighting the flowers the entire round and losing points along the way, start by taking out those inconvenient of plants. Your improved score once you have done so will be reward enough for the trouble.