I think it doesn't matter how early you start if you don't revise it well, in my experience the downside of starting too early is it makes you think you know the material well and makes you complacent and delay revising the material, the period before the exam actually counts a lot. Make sure you have two weeks of vacation before the actual exam. That's the period when you are completely focussed.
Things which worked for me to Pass L1.
Practice as many ethics questions possible just before the exam(most of the questions asked are similar in nature).
FSA is very very crucial, looked quite formidable in the begining but nailed it as I read through the stalla study guides 2-3 times. The stalla self study cds were very useful, view them at least 3 times (spent a day on each of them before the exam, viewing them and solving the pass master).
Portfolio management(makes sure you revise the Quant well) and Alternate Assets are the simplest and have a combined weight of 10%.
Quantitative analysis: Revised the formulas night before the exam. Plug in values kind of questions will be there. Don't overthink the questions.
Economics

on't spend too much time on it(unless you have lot of time to spare). Focus on the main points. Stalla cds include the important concepts, think and practice in terms of charts (e.g suppy and demand curves). Couldn't do very well as I was more focused on covering the material instead of focusing on important concepts and formulas.
Derivatives: Again think and practice in terms of charts.
Did ok on this.
Fixed Income Analysis:
Screwed up. Didn't practice enough.
Equity Analysis. Master the CAPM, DDM very very Imp.
Hope this helps.