Is it a good idea to have a protein shake after a gym workout? How do I make one?
Most health professionals agree that consuming extra protein with strength training is helpful. Some experts recommend one gram of protein per pound of body weight over the entire day, though there are a variety of studies on the subject with differing recommendations. The recent consensus view is a post-workout recovery meal is a good idea, typically within 30 minutes to two hours of completing strength training. A mix of carbohydrates and protein is recommended. 

To make one for yourself:
1. Get a good protein source, typically a protein powder. Casein and Whey proteins are popular choices. 
2. Add the protein powder to a shaker. Some are small and handheld; other models use electricity. 
3. Following the instructions on the protein powder, add water or milk. Typically, 4 to 8 oz of liquid for one scoop (30g) of powder. 
4. Optionally add your favorite fruits, such as bananas or strawberries.
5. Shake things together for around a minute. 

Enjoy, but be sure to vary your protein sources as a part of a healthy and balanced diet!