This is a natural assignment since Alphonse Mucha, illustrated advertisements in addition to posters, book illustrations and producing a wealth of other paintings and commercial and fine-art designs.
Just pick an elegant product, then do a retro style ad mimicking his decorative style and subject matter, and then use Art Nouveau lettering for the product name,
as in these Mucha advertising examples.
http://rlv.zcache.com/vintage_alphonse_mucha_cycles_perfecta_ipad_speckcase-p176487353858330606vu1z1_400.jpg
http://ecx.images-amazon.com/images/I/51fIIILJuoL._SX300_SY390_CR,0,0,300,390_.jpg
http://ecx.images-amazon.com/images/I/410EPtRB6lL._SX300_SY390_CR,0,0,300,390_.jpg
http://ecx.images-amazon.com/images/I/51RyoA9eFkL._SX300_SY390_CR,0,0,300,390_.jpg
http://ecx.images-amazon.com/images/I/51ZsiIpNNAL._SX300_SY390_CR,0,0,300,390_.jpg
Here are tons of more examples for you:
http://www.google.com/images?client=safari&rls=en&q=Alphonse+Mucha+paintings&ie=UTF-8&oe=UTF-8&oi=image_result_group&sa=X