Using protein powder to aid in muscle gain typically involves incorporating it into your daily diet and workout routine. Here is a step-by-step guide:

1. Determine your daily protein requirements: To build muscle, it is important to consume enough protein to support muscle growth and recovery. This will vary based on factors such as your age, weight, and activity level, but a general guideline is to consume 1 to 1.5 grams of protein per pound of body weight per day.
2. Choose a protein powder: There are many types of protein powders available, including whey, casein, soy, pea, and others. Choose a protein powder that aligns with your dietary restrictions and goals.
3. Incorporate protein powder into your diet: You can use protein powder in a variety of ways, such as adding it to smoothies, baking it into recipes, or simply mixing it with water or milk. Try to spread your protein consumption evenly throughout the day.
4. Workout regularly: Building muscle requires a combination of resistance training and adequate protein consumption. Resistance training should be done 2-3 times a week, focusing on multi-joint exercises that work multiple muscle groups.
5. Monitor progress and adjust accordingly: Track your progress by measuring changes in your body composition and strength, and adjust your protein powder consumption and workout routine as necessary.

Note: It's important to remember that protein powder should be used to supplement a balanced diet and regular exercise routine, not as a sole source of nutrition.