Actually, it's far more difficult to illuminate a large surface evenly. Forget the snoots (or attempts to mimic snoots) since you need illumination spread over the entire large background. From your description, it appears you have only three lights (hotshoe-mount portable strobes) to illuminate both your subject and background. In this case, I would recommend one flash on the floor directly behind your subject to illuminate the background, with the other two used to illuminate your subject. If you want all your subject (head to foot) in the image, use a boom to place the background light source out of view above your subject.
If illumination from the background source falls on your subject, attach a piece of white paper between that light source and your subject (rubber band around the strobe head), using paper no larger than necessary to prevent the illumination falling on the subject (don't want to block background illumination). By the way, white paper was suggested since black absorbs light, an undesirable result with weaker portable strobes (no need to reduce the illumination even further).
Another lighting option is two lights opposite each other at a 45° angle from the background, far enough away to provide even lighting without hot spots. This leaves only one light to illuminate your subject, which means a reflector as your second light source for the subejct. However, hotshoe-type flash units may not have sufficient power to fully illuminate an area as large as a 10-ft background in this manner. Resolve this by moving the lights closer to the background (maintain that 45° angle), reducing the area illuminated (the center of the background directly behind your subject instead of the entire background).
Still another option is not to illuminate the background at all. This allows two lights for the subject overall, as well as a hairlight to separate the subject's hair from the background. This lighting arrangement, combined with a darker, out of focus (depth of field), background, can be very dramatic.
Ultimately, the key is to experiment until your find the lighting arrangement your prefer. With enough experience, you'll be able to see what lighting was used in someone else's image and easily duplicate that yourself. Until then, keep at it.
stewart