intense physical activity.
meditation.
hot shower.
a good wank.
These are all a hugely hugely beneficial way to help relax the body and mind. Yoga is also another option, and helps with the stretching that sustanon suggested, and in itself is quite a powerful form of active meditation, not to mention a bloody good body workout. Breathing exercises also do wonders, and help to restore a natural and healthy level of oxygen flow to your body, which relaxes you. Bath salts(the REAL ones) with a nice warm bath are also bloody brilliant, and always help to calm me down after stressful day. Chamomile tea is also great for helping to relax especially before bed. And taking Magnesium tablets before bed can help quite a bit if you get restless while trying to fall asleep.
But to be brutally honest. Not sure if the OP is hard into it or not, but quitting drugs will do you wonders with helping you to relax. Sure, the initial stages of drug withdrawal from pretty much all non-herbal drugs can be really fucking hard, and the exact opposite of "relaxing". But once you move past that stage and the haze begins to clear, not only can you think more clearly in your day to day life, but you stress less, and feel less of a need to have that relax at the end of the day, cos you're already relaxed. And also, once you quit drugs, you begin to notice that the herbal drugs actually do work quite well, especially if you believe they will. Most people who use recreational drugs pretty much convince themselves themselves that the herbal stuff doesn't work before they have ever tried it. And then instead of taking it for what it is, they try to compare it with the drug counterparts, which is useless. It's like comparing coffee to apples. Coffee gives you an instant hit of caffeine, wakes you up. But apples also work really well for waking you up, but not in the same way that coffee does. So to compare the two, is useless. Especially if you already believe that the apple won't work!
Hope that helps. Just a little advice from someone who is in the process of clearing a life of anxiety/depression and 10 year drug habit out of my life. I recently realised that pretty much every mental and physical problem I have had these last 10 years, is directly linked back to my drug use. I refused to believe this was the case for a very long time. I have only now begun to see that for years I was fooling myself that recreational drugs were the only way to calm my nerves, it was quite the opposites, they were the cause of my nervous body and mind. Now I see I was wrong, and am looking forward to learning more about herbal remedies!
but yeh, if you are looking for normal "legal" otc counter drugs, just to help relax, as another form of taking a drug, then many of the things listed here work great too. kava especially. melatonin also helps, and helps to regulate sleeping patterns, which in turn helps you sleep properly, which has the benefit of you feeling more relaxed during the day! you should be able to get melatonin prescribed pretty easily by a doctor. you want the medical grade melatonin, which comes in much greater doses and purity that some homeopathic remedies!
enjoy relaxing, whatever method you choose. everyone should just fukn relax aye!!