As a general Rule, the best method to fish lakes within a few hours drive of Calgary is to 1) Try a few different coloured/ sizes of Chronomids using an indicator thats about 8-12 feet (depends on depth) above the flies and just cast it out and let it sit until it moves.. or add a few twitches or slow retrieves. You can try this method with different nymph's/ flies. 2) you can fish a leech or streamer with a floating line and 15 ft of leader without an indicator, and try different striping methods ( but this works well in a float tube the best.... just kick).. Or do a bit of both, with different flies. 3) Fish a dry fly when fish are rising (usually Cutthroat) , and just let it sit there.... this one is pretty self explanatory. The top flies in trout lakes (depends on lake) are probably Chronies and leeches, but that my opinion. A good lake to practice on that is close to Calgary would be Wedge pond out in K-country, it has grayling and chronies work well. Plus you can cast from shore pretty easy.
But like they said above, look up Bullshead posts, they will help a lot.
Good Luck,
Drew