When sitting, you need to be thinking about getting-up. This is very important because when someone comes to great you, (hopefully you can see them coming) you should be able to reach for your belongings with one easy step and shake his or hers hand simultaneously.
To make this happen, place all your items in one place to your left, in the chair or on the floor. This will make it easier for you to gather your items as you are being approached.
For women, you can reach for your handbag with your left hand, while using your right hand to pick up the portfolio and by quickly placing it in your left hand allows you to hold both simultaneously. If your bag has shoulder straps place the purse over your left shoulder keeping it tucked behind your left arm.
You can keep your portfolio in your lap, so that you can pick up the portfolio with your left hand, leaving your right hand free to shake hands with your client.