Not too much water is needed, so do not over water your plant or you will kill it. In fact the surface will get a bit crusty, use sink water that has been sitting around for 24 hours at the least to water your plants. If you can place your finger in the soil down to 3 or 4 inches and not feel moisture you need to water your plant.
Placing too much fertilizer can kill your plant quite quickly and is normally the second biggest mistake that many people will make when growing weed indoors. This is especially true when you have soil that already contains many nutrients. When you do need to add nutrients do it every other time that you water instead of every time. The different stages will like different added nutrients. While in the vegetative state you should add nitrogen, and the flowering stage should be more phosphates and not near as much nitrogen.
The perfect environment will also make a huge difference to a good weed plant. Not only do you need to focus on the temperature, but also air circulation and humidity as well. When you keep these consistent and pay extra attention to your plant you can see a difference. Believe it or not even music can help your plant out a lot.
When you are throwing trash away you need to keep this trash separate from everything else. This means those garden garbage bags that you need to throw out you need to seek another location to place them at. Never place things that can come back to you in this garbage either.
Patience is a big virtue in life and when you should harvest your plant. Sure it will be hard to wait at times, but you need to wait. Those plants may possibly put on some extra weight and give you more yield if you wait too. A good time to wait too is when you see that half of the pistils are brown.