Making Gold in Little Alchemy 2 is a quite simple process. All you will need to do is combine the elements Fire and Air. To make Fire, you must first combine Energy and Earth, and to make Air you must combine Pressure and Smoke. Once you have all of these elements, you can combine Fire and Air to make Gold.
If you want to make the gold into something else, there are a few more steps you can take. To make Gold Bar, you must combine Gold with Metal, and to make Gold Coin, you must combine Gold with Money. You could also combine Gold with Tablet to make some interesting products, such as a Lithograph.