In the realm of vaping, especially when researching things on the internet, a lot of words get thrown around that mean the same thing, or two completely different things depending on what is being written on. This happens because there isn't a lot of standardization with regards to terminology yet. One good example is the word "pull." Some sites, stores or blogs will have "pull" mean to drag or inhale on the device. Others will take it to mean how much power is "pulling" from the battery - or battery draw or drain. Whatever the case, you should know what the ideal "pull" would be across the three most popular vaping devices for both iterations of the word.
E-Cigarette: First, don't pull too hard, too quickly, or both as this could cause coil malfunction or throat irritation. Generally, draw the vapor slowly into your mouth then inhale - this is called mouth pull, and gives less vapor but also less throat hit and you are less likely to cough. Direct Pull is draw right into the lungs and may not be pleasant for people not used to it. More vapor and much stronger throat hit with direct pulls comes at the expense of using more e-liquid and more battery. Since e-cigs are probably the least customizeable on this list, you can expect to get, on average and dependent on storage, care, etc, at least a day of vaping on a battery's charge. However, the amount of time a battery will last will also heavily depend on use.
Vaporizer: As with e-cigs, don't pull too hard, as this could flood coils and get e-juice in your mouth. Draw air slowly so that coils produce good amount of vapor. Consider doing mouth hits first until you know how lung hits effect you, and even then make sure to inhale slowly. Consider exhaling through your nose - this could help you get more of the flavor and experience from your vaporizer. The power drain pull on a vaporizer is slightly more difficult to ascertain, as some level of customization and differences of use is common. Because the differences in use is likely to be the biggest factor, make sure you monitor how your vaporizer is performing to know when it is time to swap batteries or charge.
MOD: Because MODs are so customize, the ideal pull for these is going to depend on if you have your settings geared towards more vapor production, more flavor, etc. If you're chasing clouds, you probably have an e-liquid that you're good with and can do lung pulls. Still, it is important that you do not draw too much too quickly, as this could still cause flooding. Much will depend on the power settings that you have and what kind of coils you are using. With all that being said, you will need to monitor your power consumption more and more as you get into more complicated Mods, so be aware of that.
The prefect vapor hit depends a lot on who you are as a vaper, and no two vapers will have the same answer. Overall, the important thing to remember is that when inhaling on your device, you do it slowly. This will allow your coils to do their thing most efficiently, as well as keep your power drainage stable and avoiding flooding. Experiment a little and find what works best for you.