Web Design Project - Website Design Issues

Problems I can have with designing a website is sizing for example, because nowadays people access sites on their phones and iPads so the website may not look right with a small screen, a solution to this would be to create a mobile version of the site somehow. Another issue would be that the client changes their mind halfway through the project, my group has experienced this plenty of times, a solution to it would be to have weekly meetings about the site, showing them progress, etc.