Coin and Experience Farming

Ever since the 4.4 update, coin farming is easier then anything. Here's how to do it:

First Method
Get a powerful weapon like the Redstone Cannon or the Automatic Peacemaker M2, and turn the difficulty level to hard. Play Farm in Campaign and get 3 stars. Each time this happens, you will get 3 coins. It is easy and fast, just make sure to get 3 stars, or it will go slower.

Second Method
Just get as much xp as possible. Xp is earned by getting 3 stars on levels, and winning online games. Whenever you level up, you can get a big amount of coins. The higher the level, the bigger the reward, but the harder the work.

Third Method
Go on to Cooperative mode and play Team Battle/ Time Survival. Team Battle will offer coins to the winning team, and Time Survival gives coins to the players with best scores. Be sure to have good guns though.