I prefer push-pull anyway, but I'll confirm what everyone says that if you don't do it right it is just as dangerous as they say.
I've got lots of practice; I'm teaching a friend to make Flemish strings and the guy forgets something at least once a month, so when I go over I actually have to remind myself not to treat his bow like I do mine out of courtesy. It works fine if you know what you're doing.
Hope this link can help you string your bow : http://hunthacks.com/string-recurve-...hout-stringer/
Thanks all!

It will be dangerous if you string recurve bow without stringer

I usually use a stringer. But if I don't I use the push pull method when I can. I say when I can because my arms ain't very long and on some recurve bows I have trouble reaching the upper limb tip.
Besides, the stringer method is much much easier.

Stringing bow with notch on side of shoe
 

Watch that with a recurve. I saw one explode when the tip slipped off the shoe and hit the floor.

If I'm using a bow that's light or I care LESS about it I might use the step through method. But I normally use a stringer, I just see them as cheap insurance on my favourite bows.