In the Ruy Lopez, White thematically plays h3 early in many lines (based on how Black plays indicates just "how early"). In fact, the Ruy Lopez is one of the most famous openings where h3 serves a solid purpose (to prevent the annoying ...Bg4 pin). Many beginners mistakenly play weak moves like h3, a3, h6, or a6, early on instead of development of the pieces, or fighting for central control. Many beginners play these moves (usually) for the reason of preventing a Bishop on Knight pin, but this isn't as bad as most beginners think it is: they are simply uncomfortable with tension and pins in general. However, the ...Bg4 pin in the Ruy Lopez is especially annoying for White. True, h3 does weaken the Kingside ever so slightly, but the Ruy Lopez is one exception to this rule, where h3 is a good move.
Play h3 early on as White to prevent this pin. 
perhaps you can post some better example games than what I came up with in a scramble xD
I'm not that great at explaining it, but do you know how to get a pgn from any game? Once you have the game pgn (or FEN if for only the position and not the entire game), then you can use the chess-board-looking icon in your post to create a diagram. If you don't know how to get the game pgn, then you could just post the moves manually I suppose (example of manually posting: 1.e4 e5 2.Nf3 Nc6 3.Bb5 is the Ruy Lopez Opening).
When I play the Ruy Lopez with white I always get screwed up by black's Bg4 ideas with the pin on my queen, and as far as I've been looking I haven't found any lines of it which could prevent that move without giving away a tempo to black and if not by the pin I get myself a disadvantage by that anyway. Can anyone suggest me a "forced" or "semi forced" line by white in the Ruy Lopez which prevents Bishop g4 plans by black without giving away too much?