Hay Day Tips

Diamonds

Don't waste your diamonds on decorative objects or speeding up products. Use them on the ques for your machines. Dairy machine and sugar machine are a must, as you will use these to make other items.

Classifieds

When browsing the paper don't just look in the adds that have something you want in, most times if the paper has a few building material in, other shops in the paper will have building material that isn't advertised. Even if the paper is filled with eggs and bacon, still check them as you never know what could come across.

TNT

Start collecting TNT, shovels and dynamite early on in the game. You will use these on the smelter which makes ore. The ore is used to make jewerelly, and this is the best seller. You can have up to 5 smelters.

Trading

If you really want to advance in the game, then you can join a Hay Day forum. On here you can trade items with people, or ask for help on boat orders.  Also the more friends you add on had day the more slots you get in your road side shop.

Building Expansion

The best way to do this is through harvesting. Spend some time continuously harvesting wheat. I have just harvested wheat 6 times continuously and I got 1 saw, 2 land deeds, 1 duct tape and 1 bolt. So as long as you can get rid of the wheat keep harvesting. 

Making Money

If your aim of the game is to make lots of money then forget about the boat and truck orders. Everything you make you can sell in your shop. Also browse the paper and friends stalls for any cheap items, then sell them in your shop at full price. Be carefull though as something's don't sell at full price so will be in your stall a while. Keep your animal feed machines running as animal feed sells quick.

Experience Points

If your aim of the game is to level up fast then it's all about the experience points. Max out your animals as you level up and keep feeding them. Even if you don't need all the produce, you can still sell in your shop. Do the boat and truck orders as much as you can. Also harvesting as often as possible will get you lots of experience points.

Cats and Dogs

You can buy the cats and dogs with vouchers. You gain vouchers from completing boat and truck orders or harvesting crops collecting from the Mystery box. You can not trade them. When you have enough vouchers you can buy your cat or dog, but before you do this you must buy a cat or dog house. Your cats and dogs will need feeding, milk for cats and bacon for dogs. Every time you feed your pet you will get 30 experience points. They only feed every few hours. It is a achievement getting each individual pet.