Focus of the week- Workout with as heavy poundage as you can.
Use relatively heavy weights doing reps of around 8-12 (1-2) sets depending on your fitness level.
Increase the weight and do another 2 sets. It should be heavy enough that you just can not do 12 reps with.
Now increase the weight again. This time for only 1 set, and you should be struggling to get 4-6 reps.
This is how we gain muscle mass. The muscles have to be stressed to a point to where they have to do something to meet the demand.
Do this at the gym for each muscle group that you would like to round out, and made curvier.
I don't think its a good idea to lift heavy, or put too much emphasis on the abs. It can result in looking blocky and thick around the middle.
To have the small waist and rounds hips of a pin up girl, you should build your back, for a shapely V, and place a lot of emphasis on working out your rear end.
Doing these things alone will give your waist a smaller, and more of an "hourglass" appearance.