The game designer is a craftsman who creates gaming experiences, has great power and a great responsibility. If you really love that work you must have patience, be willing to abandon or restructure ideas, to work hard as a team, to continuous study, to make many important decisions and, mainly, not to give up and fulfill your objectives. 
5 tips for incipient video game designers:

 1) Design similar games

2) Collaborate with development groups

3) Opt for a simple gameplay

4) Choose a theme that motivates you

5) Never give up