Moisturizing lotion and drinking plenty of water will help dryness. Also make sure you're not over-washing your face and make sure you're getting fish oils and omega 3 and 6 fatty acids in your diet.

Smoking of any kind can make rosacea worse. Cannabis in particular dilates peripheral blood vessels, which can worsen flushing, aggravating the red, splotchy/rashy effect and can make the little visible blood vessels on your skin more apparent. The peripheral vessel dilation is the same reason you get bloodshot eyes when you smoke it, too.