I can empathize with the struggle you describe. Unfortunately, the ENSO signal doesn't always stand out among all competing factors, and often times those competing factors are more difficult to predict than ENSO months or seasons in advance. However, I still believe that the ENSO signal is strong enough to provide some guidance to farmers, as suggested in this blog post from a couple of years ago. 

In addition to checking the charts related to past ENSO episodes, I might suggest checking some forecast maps from state-of-the-art seasonal forecast models, like from the NMME (one-month and three-month maps). As you can see from those links, you can get both spatial maps of anomalies (like for precipitation) and model skill, so you have an idea how reliable the models are. These forecasts can complement the ENSO-related guidance, so you could see if the models are consistent with expected ENSO impacts, if there may be some other signal that the models are seeing, or if the models are inconsistent/unskillful for the region, lead time, and variable of interest.