Analoge or DCC.....
Analogue
If you would like an analogue operation, the LGB 'auto-reverser' shuttle unit allows up to about 1.5amp.
I started with this but soon found that, with a non-LGB loco, an incline and wanting to pull a good few log cars, that I needed a reverser that could handle more amps.
This led me to a unit that could handle up to 8 amps (from ebay and worked in exactly the same way that the LGB one did so I could use the track diodes from the LGB unit.
https://www.ebay.co.uk/itm/Shuttle-...169344?hash=item4b40e30e40:g:6scAAOSwPwla1KW8
DCC
As far as DCC is concerned...there are 'feedback' control units like the Massoth one which facilitates the programming of auto reverse etc.
A simpler 'universal' system is the Tam Valley train shuttle
http://www.tamvalleydepot.com/products/trainshuttle.html
This can handle up to 2 amps (or 5 amps with the DCC booster)
http://www.tamvalleydepot.com/products/dccbooster.html
When I changed from analogue DC to DCC I have used the Tam Valley system and it works automatically with ANY loco address up to 99 (or four digit addresses using the address adapter).
Tam Valley are a good company and Duncan McRee (the owner) is always happy to help if there are any issues.... he sent me the custom wiring diagram for attaching the booster to the shuttle unit.