Jane, I don't do Delta.
I just study the chart for the stock and mentally estimate from my indicators what is most likely to happen AND, more to the point, what I think the universe of other traders think.
In the SPY quickie just completed, I judged the stock to be headed strongly south and bet .18 that it would go further south, at least a few cents. Turned out to be the case, but quick changes on the 1-minute indicators were a clear signal to jump ship.
I say just learn to be accomplished in technical analysis of the stocks first, and then learn to apply the unusual aspects of options trading. It is complex. That's why so few succeed at it. Some go busted in the effort !