If you are planning on doing magic on the street first of all don't even concern yourself with open/middle/close, this is the furthest of your problems. You need to do research on what type of street you will be performing on, this is different from country to country, heck...from neighborhood to neighborhood in some cases.
Some streets are made from concrete, different mixers of concrete with little rocks in them, asphalt, gravel (between large and small), cobblestone or just plain old dirt. Some are smooth, some are bumpy, you have to think about pot-holes (mud-holes) and cracks...texture, and so on and so forth.
Sometimes the street get's really hot during the summer months, and traffic...have you thought about traffic? Are you starting a new sport? Extreme Card Magic, let me tell you...if you want to test your chops in magic, trying performing a coins across routine in rush hour traffic my friend!
Not fun.
So yes, walk around the area's of your town first to get an idea of what you have to work with.
Reconnaissance is key.
Okay, no magic in traffic...I tease!
Personally, it all depends on the situation if I show people one effect or 3 or 4. Sometimes people won't even stop for you, and others will stop but may be pressed for time. With those who are pressed for time I show them something straight to the point, because if you do something that is lengthy then they will start to gravitate away from you, and instead of being the guy who showed them a great effect, you'll just be the guy who slowed them down.
For those people the "Unlinking Rubberbands" is typically a good choice.
If someone(s) are playful then I'll do several effects for them, but you also have to know when enough is enough. And you'll learn through experience when you've reached that point. My opener isn't always my strongest effect, but it ranks up there...my finisher as of late has been an Ambitious card routine with a signed card, followed by Daniel Garcia's 'Timeline 2.0'.
As JH stated above, watch your angles and be aware of your surroundings. Nothing is more annoying than being in the middle of a routine and someone coming behind you or to the side depending on the effect and being like "Aha! Saw it!". Sometimes when another person walks up the attention is placed on them (especially if the person is part of a group you're performing for and maybe they were in the bathroom before you showed up) and so it's your job to regain control, and that can usually be done by engaging them politely by saying something like "Hey man, what's your name?" (let's say it's Eric) "Hey Eric, nice to meet you...check this out." etc...
Practice, perform and impress.
- Steve