There are 2 ways to increase the potency which I know work for a fact.
The first and most effective way.... hot ice! A glass jar tends to work well.... put your weed into a jar, put some hot ice in with it, normal ice wont work, you'll just end up with a soggy mess. Remember to make a hole in the lid or somewhere on the jar so that it doesn't burst. Leave the jar in a freezer for a few days, the longer the better. 2 weeks should do nicely
And vuala... your weed should be almost twice as potent.
The second way I know of... burying it! Although this takes much longer to increase the potency than using hot ice :\ But it still works pretty well. So.... put your weed into a packet/container. My advice is to seal it up really well so that no air can go in or out. Trust me... water vapour still gets in. Then, bury in a cool... dark spot. Burying in wet soil tends to work best. I buried my'n underneath the geyser pipe in my back yard as it drips quite often and that patch is always moist. Leave it buried for about 4-6 weeks. Again... the longer the better. I left my'n buried for 6... definitely worth the wait. The mistake I made was burying a full 300g block... so only the outside layers seemed to increase in potency. Breaking it up first if you are burying quantity like I did would be a good idea to ensure that all' of it becomes more potent instead of just the outer layers. A light mold can be seen covering the weed... kinda like a fungus. This means that operation 'bury your weed' was a success
You can just taste the increase in potency!! It tastes a lil hectic :\ but if you're a genuine weed smoker... its all coca cola
Trust me... this works..... enjoy