Watch the Minor Substitutions online guitar lesson by Mimi Fox from Flying Solo
There are tons of tunes that use minor chords often including minor blues pieces, and sambas with minor TWO-FIVE-ONE progressions. Pick a batch of these tunes in different keys and start using the substitutions wherever you can. They won't all work in every situation and that's why it's a great idea to tape yourself playing so you can hear what you are doing. The virtue of solo guitar is that there is no sax or vocals to interfere with you so you have more liberty. Explore!