Here is a typical scene in a gym near you...you turn up,start doing something (rolling out, stretch, moving, etc) while having a chat and catching up with your mates. You do your workout. You finish with some stretches or accessory exercises or even rehab work while you continue catching up with your mates.
Sounds familiar right?
If I can just change routine a fraction, you can get a lot more out of the usual time you spend at the gym...without doing anything more than you are already doing...
1. If you stretch, really focus on the area you want to stretch. e.g. the hamstrings. Then make sure you keep everything else still except the key joint (hip joint or knee joint for hamstrings). Really focus on stretching the key group you want, not just letting the most flexible area dictate where you move the most from.
2. If you do static holds, then again, think about the position you hold...make sure you check your position or even ask your friend about your posture during your chats.
3. If you do some extra strength work, focus on keeping your body still and making that movement as pure as possible
4. If you do extra cardio, focus on your technique - e.g. rowing
5. If you are practicing technique work for your lifting, then really focus on your positions.
Let me know how you go. If you focus just a fraction more, your flexibility will improve.