what you need to do is invest in really good hair products that will make your hair 100% manageable, Rusk or Kerastase. You should then go to Sallys beauty supply if you have one where you live, or some place like that where you can get a really good blow dryer, for around 60 dollars. It is so worth it and it will last a long time. You need a dryer with high wattage. I think Mine has 1200 Watts. You can try rollers or hot rollers, if you get slightly larger ones they wont create curls only volume, but of course since you have a bob by slightly large i mean NOT TINY but maybe 1 inchers 1 and a half. If you do that you can blow dry after and spray a litle hairspray when you are done.