Try and avoid these people. If you don't want to smoke with someone then don't, but if they have helped you out in dry periods then you should have the courtesy to do the same. That is assuming that you have enough pot or funds to purchase pot. If you only have enough to get one person high, then the choice is obvious. It would be wasteful for two people to smoke and not feel the effects, when one person could have caught a nice buzz. If you don't enjoy smoking by yourself then forget that last part and just go ahead and toke it up with a friend.
Many moochers will ask questions such as, "You got any weed?" Now just because someone asks this question does not make them a moocher. That's just a common initiation they tend to use. I've also encountered several people who will say, "Do you want to smoke?" Then after I accept the offer they inform me that they had no pot and was assuming I had some. When someone says something as stupid as that, it's much easier to say no. Other times they will try and make you feel bad for not wanting to smoke with them. Again if they deserve it and you have enough, go ahead and help them out. For the others, you must find a way to let them know you're not interested in smoking them out. If they don't know you have the sack then you could always deny that you have any, but not everyone is comfortable with lying. If you have plans for the weed then simply let them know that you're not going to cave in. If you just don't want to smoke with that particular person, perhaps tell them why. Try and talk to them rather than gripe at them for never having their own weed. That's enough about the scavengers. After all, avoiding them is only a small part of learning to conserve your herb.
Pipes or bongs are probably your best bet. They're great if you're by yourself or with one friend. Water bongs hit great and can easily get you high in three hits or less, even if the quality of the herb isn't that great. The main problem with bongs is that is can cash out a bowl pretty fast. So it's best to just take a hit or two and set it down for a while. That will give you a nice buzz that you can enjoy until you're ready to take another. Also a bowl usually takes less weed than a joint, so you can pack one bowl and if that didn't quite do the trick you can always pack another. They're also much easier to extinguish than joints which often break during the attempt. Another plus about pipes and bongs is that you can cap the bowl with a coin so the weed doesn't keep burning while you're not hitting it.
Joints can also be great tools in helping you conserve your smoke. They're typically used in "on-the-go" situations but many use them ritually. If rolled nicely, a single joint can get a small group nice and stoned. If they're not rolled properly, it can actually be a waste of weed. I'm sure most of us have seen the cherry fall off of the joint because it was rolled too loosely. Incidents like this can waste much of the joint if they're not taken care of. If you're trying to conserve and you can't roll a nice tight(not too tight) joint, then it's best to not smoke them. Just practice a lot with household kitchen herbs until you are skilled enough to roll a real one.
Vaporizers are also a good way to push your sack to the max. You get more for your money because the weed is vaporized rather than burned. Vaporizers contain a heating element near the bowl so that the pot gets hot enough for the THC to be released, but not so hot that it destroys the matter. When you light a normal bowl, the contact with the flame destroys some of the THC before you get a chance to inhale it. Vaporizers eliminate that problem. The smoke is much harsher than regular smoke, but you can get a lot of bang for your buck with one of these machines.
There's not very much that can be said about this part, it's rather self explanatory. Just consider how many sessions you wish to get out of the buds you leave behind. Also consider the quality and how much it takes to get you high. Put aside the appropriate amount, then go out and get high with your friends.
(NOTE: I'm not referring to the rolled up cardboard filter that some put in their joints. If you do this then you can skip this section for it does not exactly apply.)
Before you put on those roach clips, think ahead. If you smoke joints or blunts(blunts are not good for rationing) frequently the roaches can really add up. Get a small container to keep them in, Altoids or other breath mint tins are ideal. You can even put out the joint a little early if you're already high to save a little extra. A nice sized roach is a bowl for later. If you keep saving them and maintain a collection, you can end up with a nice little stash for a rainy day. Also roach weed is usually more potent because the joint resonates itself as you inhale, leaving you with concentrated THC.
If you roll up a new joint with the roaches of previous joints, you have created what is referred to as a "second generation joint". Now this concept can be taken further and you can save the roaches from the generation joints and roll another. That would be a "third generation joint". You can keep this going as long as you'd like to make one very potent joint.