I have one piece of advice:
Work on strumming LAST.
I'm presuming that because you're interested in strumming, you're a singer as well. If so, learn the song first then work on strumming patterns, rhythms, etc.
When I learn a song I want to play, I make sure I have the chord progression down to where I can play through the song with a basic rhythm/strum. Once I have the chord progression and the lyrics down, it's natural for me to then work on strumming and rhythm. I usually try to replicate what I like about the rendition I'm covering.
I believe that anyone who favors strumming before actually learning the chord progression and the lyrics will eventually frustrate themselves because they will be trying to put together too many unfamiliar pieces of a formless puzzle.
As you can see I view working on strumming as a "tweaking" part of learning a new song. I tell my students who are concerned about learning strum patterns, that they should listen to their favorite rendition and simply work on copying what they hear (in terms of rhythm).
I hope this helps. Please check my link and listen to some of my MP3's to see what I'm talking about in my own presentations.
http://www.4shared.com/file/118539723/f8ce7bfe/Besame_Mucho.html
click on my email address next to my profile picture to access other songs.