Hope you don't mind the 'behind the scenes' question, it's 80mph winds on the tops today so I figure you guys will be likely at home rather than out this weekend!
I don't mind at all
I suppose planning a trip involves everything you mention but the one thing which usually rules over everything else is the weather.
For this paticular trip as April mentions in her TR we ( or I should say I ) originally wanted a camp somewhere near the High Gait Crags area on Esk Pike the reasons being that A I have never camped there and B I love the view of Upper Eskdale and the Scaffells from there.
As the week progressed however it was obvious that the forecast was for high wind and low cloud in the central/western lakes so I started thinking of routes we could do in the far east fells. This also fitted in with the logistics of our trip ie. I was coming on the train to Penrith and as April lives in the north Lakes this was the most convenient pick up point.
I then remembered that I had wanted to visit the tarn on Howes ( that's the bagging angle covered ) so It was then simple to make a circular route from Mardale and as a bonus I discovered that April and Beefy had never walked in Swindale or visited the falls.
As April mentions again when the weather deteriorated on Saturday evening / Sunday morning we altered our proposed route to visit the bothy and come back over Gatescarth. This is another factor in that plans are not set in stone and can be altered to suit weather, fatigue or couldn't be arsedness
After saying all that the Lakes is such a wonderful compact area you probably could stick a pin in the map and have a great walk