I also find that a page that looks professional goes a long, long way.
Don't ask for anything that is not needed - with one possible exception: a notes box for the customer to complete.
I often see orders with an order for a spare part which the notes box states "Is this the right one for a <manufacturer> <product>?"
That's good for them, they think I'll double check it! And it's good for me - because I can double check it and sometimes people have ordered the wrong thing - it saves refunds and replacements.
Physical address and your phone number helps a lot. In the UK, we have local rate and national rate numbers (usually 0845 and 0870) and these seem to have an affect on peoples perception of the size of the company. And yet, they are very cheap, much cheaper than a freephone.
Other pages in your site must match the payment page. So, if the payment processor page requests credit card name, address, postcode, phone number, email, then if you allow them to enter a seperate delivery address, these items must be in the same order and same format.
Don't force the user to enter details in a specific format because there will always be an exception. Don't force them to enter a space every four digits of their CC number. Don't force them to NOT put spaces. Let them decide. A telephone number may have 10 digits in one country, but what if they are extension 2256? They may want to type 'x2256' at the end - do you let them type an 'x'? Have you allowed for more than 10 characters to be entered? Do some people type the number with a '-' separator or area codes surrounded by brackets? Let them!
You can try as hard as you like, but the payment page is often where people stop to find out the price of an item. Too many places (like Amazon) have complicated delivery terms and it is much easier to fill up the basket and continue to the payment page to see how much it will cost. They may do this with a few suppliers, but only one gets the order.