Some videos from the 2015 World Championships in Russia.
Please view these videos and look at what the swimmers have/do in common as those are the traits that most people can adopt. Most swimmers do something that works for them but maybe not for everybody.
Here are some freestyle videos from different championships to watch:
2015 Women's NCAA 100yd Free
2014 Nov College Inv Women's 50 Free
2013 World Champs Men's 50 free forward to 6:15, 8:02, 9:47, 11:27, 13:26
2013 World Champs Men's 200m Free, watch the under water part and the video from the stands.
2012 Men's Olympic 400m Free Stroke is a little longer and some drop their elbow and it affects their catch, great race and good technique. Forward to 3:30
For all the videos watch the catch/beginning of the stroke, rotation (shoulders and hips at the same time), recovery (high elbows), hand entry (where - in front of shoulder and not to far forward), kickType your paragraph here.