I don't have any specific settings. Typically I'm using it to post a clip or something that I recorded. But what I would recommend is being careful with the volume output of the Stiletto as if it's too loud it overmodulates the sound and it sounds awful.
As far as MP3 settings I believe you can set the sample rate which changes the file sizes. The better the sound quality the larger the files. You need to find a happy medium. Also, talk radio requires less quality than music.
I'm sure there are expersts here. Perhaps just a new topic asking for help with total recorder will get you some answers.
There are other recording programs available also. Some are even free. Freecorder comes to mind. So if you don't like total recorder search for others too. I just know that many on the forum use total recorder.