I think videos are handy but even the silver only ones can't be relied upon for a complete strategy. Eg - they usually have max CRed units and most beginners/intermediate players won't have those.

Also pay attention to the Prince's level in the videos. Thats the true indicator where they are in the game. Unless its from another player of a similar level in the game it won't help much apart from a general idea of what units to use, where to place, timing etc.

Know your team, know how you like to play. In my case I generally prefer Witches over Archers so I'll go 2/1 instead of what most people recommend in 1/2. But it can also depend on how lucky you get in the Shrine. sometimes you just have to use what you've got and fill in the gaps as best you can.