When it comes to having your vehicle towed, there are quite a few events that could lead to the need to call a towing company yourself. For the most part, I'd recommend getting roadside assistance coverage through your auto insurance. It is generally super cheap (I think I pay like $6/month), and it can allow you to avoid unexpected costs with roadside assistance and towing.
Depending on where you live, towing can be pretty pricey if you don't have coverage. The industry as a whole tends to get a pretty bad rap from the bad apples. There are countless stories from people who have been quoted a particular price and then were quite surprised when they were asked to pay far more than the quoted price to get possession of their vehicle.
Some key things to look for when it comes to finding the right towing company are prior customer experiences, length of time in business, and if they have the right equipment for the job. Many higher end cars require a flatbed with a hoist to keep from damaging drivetrain components.
If you don't know anyone locally who can refer you a good towing company, Google reviews can be a pretty good source. Take those reviews with a grain of salt though as dissatisfied customers are far more likely to write a review that those who got what they asked for.
Having the right equipment is a key element in making sure your vehicle is taken care of. The good folks over at Newport Towing and Recovery answered a few questions for me when I asked about equipment. They do towing in Newport Beach and I asked about what kinds of equipment might be needed for towing luxury vehicles. They explained that every tow they do for higher end vehicles involves a flatbed. They also often used a hoist for the vehicle because they are so low to the ground that the flatbed ramp angle doesn't work for loading and unloading the vehicle.
The key takeaway is that you need to do more than 10 seconds of research when you will be trusting your vehicle to someone else. Call them and don't be afraid to ask questions, and above all, a friend who had a good experience with a company is always the best indicator.