Can you see this pic? I shortened and appliqued my sons shorts for my daughter. Yes I'd suggest you use bondaweb, you can get it by the meter (or half/qtr) or in small sheets. You can either hand sew the edges if it's too tricky to get the machine into small spaces, machine would be better though.
I would suggest that if you chose to you your machine that you start with large pieces as smaller pieces when applique-ing can be a nightmare even for an experienced machinest. Loads of fun though. Perhaps a test piece before starting on the clothes? Girl cushion cover or something fo dd?
Although something my sis used to do for girlying up which is easier then applique is to apply lace to pockets etc. Quick and simple fix to allow the girlying up but still allowing some applique to be applied in own time. <short of time to get planned projects done and still have 2 pairs of holed trousers that had planned to turn into shorts for the 2nd half of the summer term>
Sewcrafty that's exactly what i want to do! i'm fairly adept with steering the machine as it goes v slow or super fast because of its fairly worn foot pedal. (it was my grandma's machine so it made a lot of clothes for me when i was little!)
CHBID the lace idea sounds good too! i might add some ribbon/ lace to ds' winter coat which is fairly boyish khaki green but with some pink ribbon or lace would be rather fab!