Avoid those areas when waves are large or strong currents are forced to flow over them. Waves steepen and break on beaches and shoals. Generally, try to avoid landing in surf with a loaded kayak. Avoid surf on rocky beaches. Seas become chaotic.
Cliffs limit landing sites and can cause chaotic rebound wave conditions.
Make yourself visible and never assume you have been seen or have the right of way. With the exception of the tides, large lakes pose most of the difficulties and dangers of the sea. The basis of safe sea kayaking is sound judgment, self-responsibility and technical competence. Remember that where you paddle, others will follow.