Farming

Manual or automatic ? 

Melon Farm (automatic)

Sugar cane Farm (automatic)

The pistons push the sugar cane into the water where it all collects in a pile.

Sugar cane farm (manual) 

Why build a sugar cane farm you ask? 

On servers with an active economy sugar cane farms can be a good way to make money.

The example shown above is an example of a three story manual sugar farm.

  

Sugar cane farm automatic

Here pistons will push the sugar cane into the water were it will float to a collection point

Automated farms use redstone wiring and water flows or pistons in order to farm vast areas in just the push of a button or the pull of a lever, however these farms can often be unsightly and complicated to construct. 

Manual farms often look preferable to the their automated brothers.

Manual farms can be constructed relatively quickly and do not  need any complex wiring, however you might have to get your hands dirt because these crops won't harvest themselves.

 Be sure to surround your farms with fences and lighting,  to stop mobs  destroying your entire crop

Cobblestone generator/farm

If your tired of being in those dangerous and cramped  tunnels, and all you need is a little stone, the cobblestone generator is for you.

the flow of water can also be used to transport the stone away

This handy method of farming rock only needs to things to get started; a flow of lava and a flow of water, where the two flows meet cobblestone is made.

Using a pickaxe  the stone is easily mined without having to dig a hole in the ground and climb endless ladders. The supply is limitless so the landscape isn't ruined too.

A collection bucket means the farmed stone isn't just washed away.

Just to show it works ;) 

Animal farming 

Open or enclosed ?

Egg farm

There is no need to run around chicken chasing with the egg farm

The chickens are put into a small pen that has a single water flow, the water pushes any eggs  into the collection point. There is no need to run around chicken chasing with the egg farm

Using half slabs a collection point is made, this because the water will not flow through the half block space but eggs can be picked up through it.

Cow catcher

If your can't wait for that new leather jacket but don't have the time to find and catch your own cows try building a cow catcher.

Using a powered mine rail to push the cart a cow can be captured. When the cart enters the pen through the  fence gap it catches a cow and is pushed back out when it hits another. 

One cow in a cart

The cow cannot escape and can be dispatched of (humanely with a sword of course).

In order to ensure the cow catcher operates effectively the pen must be filled with cows, and it must be at least two fences high in order to stop cows jumping out.