Can you advise some simple, robust maybe not perfectly accurate method for the automatic time series forecast. It should consider seasonality and trend and works both for stationary and non stationary data. Some data are seasonal, and some not, the season period is very different. It may not model residual or cyclic patterns. Just some approximation that is pleasant for the user eye and looks like reasonable forcast.
I have tried seasonal ARIMA, ETS, and looks like it not working even reasonable good for general case and I should fine tune it manually for a lot of cases. That looks like a huge of work.