I used to compete in powerlifting a few years back, and continue to use heavy resistance training in my workouts. Powerlifters have a reputation of being big, strong, and completely immobile and stiff. The truth is, those guys just hate doing mobility work, so they don't do it. There are plenty of PLers who do it and are both strong and very mobile. I have definitely seen a similar trend in the general fitness crowd, as well as in golf community. I play with guys who know they're not the most limber or have some chronic tightness, but just hate doing any type of mobility/stretching, or even just a light warmup before hitting the range. Sure enough, they don't feel too great after 18 holes or 200 balls.
I include myself in the group who has trouble staying on top of mobility because we just don't like doing it. The fun stuff comes after the warm up and so a lot of us skip over that part. If you feel that way, try giving these routines here a try. These are from Joe DeFranco (defrancostraining.com), who is an awesome resource for strength and conditioning stuff. The routines are simple, relatively short, and very effective. I keep it simple and do this before every workout and golf outing.
If it's been awhile since you've maintained a consistent mobility routine, you're going to feel like you have a new set of legs after the first few times--it's fantastic. Tennis ball works great if you don't have lax balls lying around. The next video is Joe's "Simple Six" focused on the upper body. This has helped me work through nagging shoulder tightness for years now, and is a great compliment to the "Limber 11".
There you have it. As Joe says, there is nothing special about these routines other than they are quick and easy, so people actually do them consistently. For about two years, this is all I did for mobility and I had never felt better. Before your next round, give this a try and see what you think, especially if the warm-up is your least favorite part of the day!