The most common thing for smokers to want is something small and discrete but as they progress they may want more battery life which means their device will get bigger and bigger as the larger the battery the longer it will last.
In our opinion the best place to start is with a mouth to lung starter kit as it will feel the most natural to you as a smoker. The great thing about mouth to lung is it doesn’t have to be huge to last you a full day as mouth to lung vaping isn’t as taxing on the battery as direct to lung vaping is. This is the reason the cloudier of vapers carry such large devices. If you are a heavier smoker and want something discrete a pod system maybe the right choice. They come pre filled or refillable and are usually very small. The links below will take you to some examples and some more information.