Non-competes must be realistic.
Generally, this means that you are able to protect propitiatory information, customer lists, a realistic service area (usually 1 or 2 hours from office) and they tend to be "good" for a short time frame. More importantly, if you do a non-compete you must be willing to invest the money to enforce it (provided your state recognizes them).
As a real world example, Ohio recognizes non-competes, but even with providing statewide services I had to list each specific service I offered, a general description for any "proprietary" skills and/equipment I used, and was limited to a maximum service area for general wildlife removal to 1 hour from the registered office location and bat exclusion work to 2 hours for a maximum of 2 years. Then anytime I found a violation, I would need to pursue it so I didn't create a "favoritism" issue with one former employee saying "He allowed this other guy to do it, so why couldn't I".
In short, unless you have a very specific type of equipment you have made or manufacture yourself or have some sort of training/service method that cannot be found in any book, video, or Internet blog/message board you'll be limited with preventing someone from competing with you if they really want to. On the flip side, a decent non-compete does make it easier to prevent an employee from leaving you to work at a competitors company. So for that reason, I feel they are well worth it.