Use the generic routines as a model, experiment with them but keep the basic elements (never change more than one or 2 things per month I'd say). When you get tired of one, try another one that's radically different. Develop a repertoire of routines and gather knowledge about how your body responds along the way. Look for movements, rep schemes/ranges YOU enjoy doing primarily. A lot of people take exercises that completely obliterate their muscles, I prefer movements that my body is naturally good at and that leave me capable of important daily tasks such as walking, bending over etc. .
Ever since I got back to lifting around christmas I've been doing a push/pull/squat variation essentially (though it's more a push/pull, pull/squat, push/squat) and have slowly permutated from a 8x3 to a 5x5 to pretty much chaos and pain ranges now. I love it because I can choose from 5-10 heavy compound exercises, finish my 2-3 major exercises quickly (I find I recover much more quicker from a set of 3 than a set of 8), and still have time to do whatever else I want to do in the gym that day. The routine I follow might seem loose, but it offers enough latitude than I could go to the gym sore as hell and still have a great/enjoyable workout.