there are so many different ways to find support & resistance.. pivots, fibs, swing highs and lows, round numbers, numbers that correspond with the aligntment of the moon and the stars...lol...
the bottom line is, you'll never have EVERY price level of support and resistance on your chart. and neither would you want to.
BUT if you pick a few ways to identify them, then identify and trade them consistently, chances are you'll do just fine. i think a good rule of thumb is, if you can clearly see it on your chart, its tradeable. chances are there are a number of other traders out there who are looking at the same price level as support and/or resistance. hence, price will react there.
just my 2 cents..