How early to get to Edinburgh airport?

Two hours is officially recommended, but if you don't have any check in bags, you can probably get away with slightly less. However, as presumably a non EU passport holder, it may take a little longer, so we are back to 2 hours. Edinburgh is nowhere near as busy as any of the London airports.

I would give yourself 2 hours especially if you check in a bag.Edinburgh airport is getting pretty busy these days but they do try to move people to airside as quickly as possible. The new security area has had it problems of late but seems to be running much more smoothly and certainly when I have been through the airport a few time in the last couple of months it has taken me less than 15 minutes but times can vary.
As to getting there , trams from the city centre takes about 35 minutes and run roughly every 10 minutes. You also have the airport buses also running every 10 minutes and take about 30 minutes.http://lothianbuses.com/timetables-and-maps/airlink.
I do prefer the bus, much more comfortable, and it stops right outside the terminal , the tram leaves you a few hundred yards of a walk.

can you tell mw which airline you are using to get to heathrow and if you are checking in a bag, I canmaybe let you know what I think of their check -in times at Edinburgh, some companies are a lot better than others.

For a domestic flight in the UK 2 hours is unecessary, more often than not it's the airport reccomending that as a ploy to have you in the airport for as long as possible spending money in the overpriced shops/restaurants!;-) 60-90 minutes is fine imo, particularly if you check in online and /or have hand baggage only. Given the security issues previously at Edinburgh I'd tend towards the 90 in this case.

As this is a domestic flight within the UK I don't really see how the nature of your passport is relevant. Only BA fly from EDI to LHR, their website gives a minimum check in time at the desk of 45mins:

http://www.britishairways.com/en-gb/flights-and-holidays/flights/flights-from-edinburgh

Thanks, everyone. I am checking a bag (I know, I know.) so I think I'll shoot for two hours, but I won't freak out if it turns out to be a bit less than that.

if you are flying with BA they are usually very well organised with plenty of staff on to help,but it is usually just the one line for all flights, so if you are pushed for time let the staff know.Don't hang about downstairs , as soon as your bags are dropped off get upstairs and through security as that is where any delay might happen.

The official guidance is 2 hours before domestic flights and 3 hours before international flights, but many people make do with an hour less. I'd say arrive 90 mins at most before a domestic flight from Edinburgh Airport. It's pretty small and well organised every time I've been.