Over the years I have hired people to do work that I or DH were unable to do ourselves. But, recently, I have had many more experiences hiring handymen and landscapers as I got my mother's house ready to sell. Actually, it is DB's and my house, but I always refer to it as mom's.
The biggest two problems I have had hiring workmen is: Weeding out the people that just want to make a quick buck and have no intention of finishing the job or doing an adequate job, and miscommunication which results in the job not being done in a way that meets my expectations.
The first problem is fairly easy to fix: references, references, references. Talk to your neighbors, call your county Consumer Affairs Office, or check to see if your community has a list of recommended workers (condo or homeowner associations). I will say that it is possible for the worker that did a wonderful job for your neighbors and relatives to suddenly hit a bad streak when you hire them. That's where the remedy for the second problem comes into play.
The second problem is communication. I remember walking around a home with a well recommended handyman telling him what I wanted done and how, while watching him take notes. When he said the job was done I returned to pay him and found that about 30% of what I had asked for was not done. This went on three times before I would pay him (big rule: don't pay in advance). He was a nice man and I finally figured out that he was hard of hearing. He only did part of the work because he only heard part of the instructions.
Before you hire someone to do a project write (print) or type out in detail what you want done. Include a date for the job to be completed. If the worker doesn't provide a written estimate, then include the cost. Also include the condition the work area is to be kept in (clean up at end of day, sweep for nails at end of day, where to store supplies).
Have two copies for both of you to sign and date. If the worker balks, then they may not be the person for the job. When the work is "done" walk the site with them and check off the list. Make the worker complete the entire list before you make payment. This may sound harsh, but it provides a great incentive for them to finish the job correctly. If they offer to write your entire list, as is, on their company's estimate sheet; fine, as long as everything is there and you get a copy.
Now you have a document (contract) that you can take to court should the worst happen and the worker has a list to refer to when doing the job. Trust me, a little effort will save lots of heart ache.