All good advice, I don't shave my legs, but I have used a straight to shave the legs of others. It can be done, and in an experienced hand can easily provide a smoother longer lasting shave than a disposable.
The advice I'm going to reenforce here is the same I tell men who are starting out...
Start slow, take your time and do the easiest parts the first shave.
Don't try to shave your entire leg (or face for the guys) pick an easy spot. Sit where you are comfortable, and shave the top part of your thighs. finish with your disposable. next shave, expand that area by a few inches, and maybe try on the side, or on your lower leg somewhere. Build up your skill and confidence slowly, and ignore your knees and ankles until you feel ready. There is no shame in finishing up with a disposable. It took me 6 months before I was ready to put my Mach 3 away for good, and another 2 or 3 months before I decided to chuck it.
The other thing I will encourage is to buy a nice badger brush, and good quality soap, or shave cream. check out
Mama Bear's and
TGQ