The word process often has negative connotations these days, summoning images of rigid systems and practices that are followed just because the rules say so.
To me, a process is simply the way things are done, be it pre-planned or not. People tend to do things like they were done earlier, and over time this becomes the norm, the process.
The meaningful question to ask is: is the process working?
In my opinion, these are the most important characteristics of a good localization process:
Minimal manual work
Nobody wants to spend precious work hours doing manual copypasting. Localization involves working with text, and that alone may steer a process towards copying strings and files. Besides being tedious, manual work is error-prone.
Localization can be largely automated, so consider the bottlenecks in your own process and make an effort to eliminate manual steps. Increased efficiency will follow!
The best-case localization scenario is having all source files finished long before deadlines, translating and testing them once and having the product finished well ahead of schedule. Real life rarely works this way, but localization still doesn't need to be the last step done in a hurry just before launch.
Be aware of all the steps in your process and how much time they generally take. Don't forget to schedule the final verification testing rounds and remember to book the artists to finalize localized marketing images. Strive to find a balance between giving the translators and testers enough time to do their work, while allowing for small last-minute changes. Aim for bigger, predictable chunks of localization work instead of a constant stream of bits and pieces.
Localization quality does not solely depend on how good your translators and testers are. Having a process that ensures sufficient information for them to do their work well has a big impact on quality. Paying attention to localization requirements while designing and coding the product will also improve quality and help avoid problems for example in fonts and layouts.