have a look at "tactical asset allocation" and also combine that with various trend following strategies but you cant go far wrong with Asset Allocation
A book called Dual Momentum, or look at sites such as allocatesmartly.com
as for timeframes, mostly you'll find monthly, but you can still easily make it work with weekly timeframes
the only automation i use is for backtesting, otherwise if you have a good list of ETFs you'll not need any automation