In reply to Hammy78:
How about a multi-day trek from Valloricine along the Aguille Rouges and down towards Servoz. Walking along the aguille rouges you can enjoy the lovely views of MB and there are loads of climbing/ scrambling options en route. As a solo walker you are not going to be on the glaciers which does limit you quite a bit. Lac d'Emosson is quite cool too. You could either stay in huts or camp depending on your budget/ the weather!
Cheers
Jez