i think you need to research your plan a bit more.
the biggest question you will face is leverage. you can decide the level. If you buy physical then you are 1:1 and a trading a/c can be 100:1 up to 400:1 if you want.
the next decesion is where is you stop if you are going to have one. remember you are calling a top.
lastly i suggest planning your trade. what is entry? what is the target? what is your plan for handling your stop loss. do this for each pair you are investigating. target the currencies you want to trade.