This game's developers are very good at offering Golden Bacon (the premium currency) for free: and a lot of it! All you have to do is watch ads when you have the chance and I strongly recommend doing so. On most occasions, ads will reward you with regular currency only, but every now and then you'll get the chance for Golden Bacon. Make sure you take that chance because you can put that bacon to really good use. If you don't like tapping that small bar at the bottom of the screen, you don't have to! Simply go to the Premium Upgrades and purchase the first one: hold for pigs. You get it for free and it's enough with 2 pigs per second, but you can invest a bit if you want more.

Fortunately, as I have already said, the game's developers are giving a lot of Golden Bacon for free. That's good, because we need a lot of it anyway, so make sure you spend it where it matters the most. One thing you should NOT spend it on is boosts. Get the profits from watching ads and never spend Bacon for boosts. Instead, invest in researching Premium upgrades because they will help you a lot in the long run. The best part is that premium upgrades stick with you when you build a new Farm or when you Prestige.

Here's how I would recommend purchasing Premium Upgrades:

Hold to Clone: get at least the free one, but ideally one more afterwards. It simplifies everything a lot!
Bird Caller: It might sound strange, but later on in the game, you get more coin value per Golden Bacon spent in my opinion, as long as you collect often from the Storks.
Super-Yum Spirit Bacon: Also helps a lot in the long run as you get more spirit bacon and their bonus increases.

Every now and then, storks will appear on the screen, holding a bag in their peak. Tap them and you will collect some money - the value gets bigger as you progress through the game. But it surely piles up and helps you make a lot of money fast - and sometimes you even get Premium currency!

There are also some eagles flying around every now and then. They are extremely fast, but if you manage to tap one before they go, you get a huge amount of money. Eagles usually make a sound before appearing, so it would be good to have your sound turned on when playing Tiny Pig in order to make sure you're ready for them.

The best strategy for catching storks and especially eagles is to zoom out at maximum - otherwise you don't stand a chance!

Spend your money on research in the game in order to improve profits. Early on in the game research is important and you should always focus on those upgrades that directly influence your profits - like sausage value and earnings.

Your farm value is influenced by the number of pigs you have in your Shedding Centers, so you should focus on maxing those out ASAP because upgrading sausages gives you better money and in return makes it easier for you to progress faster.

It's not fun to start over, but you have to do it eventually. Find the right balance between prestiging and progressing, and your job for each new reset will be a lot easier.