Start with a small surplus
Muscle gain usually works best when you eat slightly above maintenance instead of massively overeating.
Keep protein consistent
Protein supports repair and growth. It should stay reliable even when your calorie target changes.
Carbs help training
Many people feel and perform better in the gym when they have enough carbohydrates around training.
Watch your rate of gain
Gaining too fast can make it harder to tell how much of your progress is actual muscle.