A good number of the items and processed resources in Ark are something that you will need in quantity. This makes producing in Bulk, or Mass Production an important factor. Luckily most crafting operations can be done in bulk, and most of them can also have their crafting speed doubled.
One of the easiest ways to double your crafting speed is to use one of the Rockwell Recipes called Focal Chili. Focal Chili increases movement speed by 25% and increases your crafting speed by 100%. This does require a bit of Farming to get all of the ingredients, but it is more than worth the effort.
The only type of crafting that you cannot use more than one crafting station for is Basic Crafting In Your Inventory. All you can do is use the above mentioned Focal Chili to speed up this process.
For the actual crafting stations, such as the Mortar & Pestle, Refining Forge, Smithy, and Fabricator, you can set up and use more than one at the same time. Of course the initial investment in resources to build multiple crafting stations can be a small problem, but if you are going to be crafting a lot and are impatient, then this will be a time and frustration saver. Keep in mind you'll also need a lot more space if you are planning to build several of the larger crafting stations.
It's also a good idea to keep in mind that for the Fabricator you will be using more Gasoline and you'll be using more than one of them. This can still pay off for large production amounts or if you are simply in a rush.