When I first started with this hobby, one of my greatest challenges was to keep my smoker lit. I watched various videos of how other beekeepers lit their smokers, so that they would remain alight for long periods of time. Some of these beekeepers, (or at least one of them!), suggested that it was easy, but I was not successful straight away.
For those who have had difficulty keeping a smoker alight, I seem to have found the secret - because I have now been able to get mine to belch forth clouds of smoke after a few puffs on the bellows, even when I deliberately left the smoker alone for more than an hour, as part of my experiment.
The old adage of "Where there is smoke, there is fire" is applicable here, because you MUST have fire (or at least glowing embers) inside the smoker if you want it to produce smoke. You cannot expect a smoker to function if it does not have sufficient heat at its core.
When I light my smoker, I use wood shavings from my woodworking machine, but you could use other types of kindling material. I deliberately use the bellows as much as necessary to get a fire burning well, to get the firebox properly heated, and then start adding pine needles (I use needles from Pinus Radiata), but I believe that best results will be achieved from using well dried fuel which has been previously collected and stored, rather than dry material which is collected from the ground in the vicinity of a hive.
It is important to keep operating the bellows to keep the fire going, because the addition of fuel at this point can easily smother the fire. It is now just a matter of pumping the bellows to keep the fire burning, and adding in (packing in) more and more fuel until the fire box is packed fairly tight. This method, of having the fire box packed tight with fuel, seems to be the essence of the secret to keeping the smoker functioning for an extended period.