No rule on frequency of strokes. You can tell by how the fire is responding just what to do and that depends sort of on if you are starting a new fire or trying to save one. Or on your general level of desperation. :-) The size of the bellows also will dictate the frequency. After your 3rd fire you will be an expert.

Generally a bigger bellows is better because you can deliver a long even blast simulating yourself blowing on the fire. I happen to at present have a real small bellows which translates to more strokes.

Time yourself blowing out a good long breath and try to make a bellows big enough to approximate that timing.

For best effectiveness try to brace the nozzle on something to hold it still while you pump so you can keep it aimed directly on whatever spot (or each spot) you choose.

I had no idea someone had answered my old question. I hope it's not too late to say "thanks mypix" ; )

If anyone is interested you can check out my origami fireplace bellows in the link.

Comments are welcome : )

Here is a link that might be useful: ORIGAMI FIREPLACE BELLOWS