For online shopping, I always use my credit card and occasionally shopping vouchers I get as a way of payment from a few survey sites that I work for. I find using credit card the most easiest and convenient option although I have a strict code of not exceeding the certain limit that I have put for myself so that I don't have any trouble paying the money back. I used cash payment only a couple of times but it is too inconvenient, you have to keep the exact amount in cash ready and that is quite difficult.
It depends on where I am shopping. When I am shopping online, I do not have option to pay with cash, I will have to use cards or paypal. However, when I am shopping off line I have two options: pay with cash or pay with cards. Which payment method I use depends where I am shopping. As long as card payment is available, I use card and when card payment is not available I use cash. I use cash to pay in street market and small stores.