This has been on my mind lately as well. I realized that to fully understand the chart takes a considerable amount of time. I like to spend at least 1-2 hours at minimum, exploring the rashi, the yogas, the placements, and all the same from the moon sign, and then also looking at divisional charts, dasha periods and the transits. Once the confluence of all these has been assessed, accuracy is greatly improved.
For this reason, decided to offer two tiers of service, one tier would be the "industry standard" of studying the chart for 60-120 minutes before the session even starts. The other tier, would take into account the massive amounts of information that needs analyzed, and takes multiple hours over a period of many days to analyze. I've found this particularly true for Varshapal. Doing it this way greatly increases accuracy and precision.