Most of the doubles I've seen haven't been bad. I've cased many without incident. On public tracks, they are usually pretty tame. As long as you clear the upside of the second hump you're good. Here's a 80-90 footer. You can see how they flatten out the landing just incase. The down side is another 5-10 feet to the left (out of the picture).
I've worked my way up to the big jumps over the last two years. So far (knock on wood) no disasters yet. Like Ben said, just take it slow. Find a jump that is good for you. Once you dial it in, find the next. On go for it if you are confident. If there is any doubt, save it for another day.