Renewable energy sources (RESs) can reduce carbon footprint, meet the increase in load demand, and reduce losses at low running cost. Microgrids, incorporating RESs, have several challenges concerning power quality, protection schemes, and control especially in island mode. This paper focuses on presenting the power sharing problem and different factors affecting it. In addition, it presents different control trends to overcome this problem. The presented control techniques are based on droop control as it is simple, communication-less, reliable, and allow the parallel operation of RESs. Finally, a comparison between these techniques is conducted in terms of controller response time, controller transient overshoot and THD. Another comparison is included to reveal main features, advantages, and disadvantage of different techniques.