Those areas are a bit tough to shave. Take your time while attempting to shave there. One thing I do is make a variety of faces to flatten the skin where I am shaving. Making an "O" face helps. I also use my tongue to push out gently on the corners of my mouth. That helps a bit too. Finally, just remember to use no pressure. You'll probably have to shave at a slightly steeper angle so be careful.
[COLOR="DarkSlateBlue"][SIZE="3"][FONT="Comic Sans MS"]Victor[/FONT][/SIZE][/COLOR]
[B]Razors:[/B] Merkur HD (34C)
[B]Brushes:[/B] Rooney 1/1 "Super Silvertip"
[B]Aftershaves:[/B] Nivea Extra Soothing Balm, Pinaud Clubman