As designers, there are a few things that we like to see in a good poster. For one thing, we like to see a good balance in type/graphic proportions--typically a solid 20/80 ratio. Secondly, we like to see that there is a cohesive feel to the poster overall. No awkwardness upon the eye allowed. Empty gaps, too much going on, or anything else that detracts from an appealing canvas that shows what is meant to be showed should be left out. As far as playing with the text goes, I think its pretty much anything goes, so long as everything is legible. Depending on what the designer is going for, be it a clean cut look or a worn down-textured feel, its always good to see interesting use of color selections and borders as well.
Based in Seattle, Washington, Nat Damm is a poster designer by trade,and has been involved with the Northwest music scene for some time now and has some really amazing work up on his site in addition to some cool shirt designs.
Jean-Claude van DAMM these are fine.