My first real graphic design job after graduating from College was at a local print shop. Before then I would work at home as a freelance graphic designer and I felt at ease completing all of my design work for clients without hassles. Anyway, so the first week working at the print shop my boss commented that I was working too slow. That week I had to get to know the printers and get use to working at the required speed level. I wasn't the greatest, but boy did I try and he also questioned if I chose the right career path. After months working there they let me go and said I was a hard-worker but slow. This discouraged me from working in a professional studio because I am worried if I am capable of producing quality designs quickly. Any advice from people who work in professional design studio?
The simple answer is that only practice and persistence are what will improve your workflow. I had exactly the same problem in my first design jobs - always feeling slower and less capable than others. My advice is don't worry too much about the long term right now. Focus on trying to improve on some small aspect every day. It might be as simple as learning a shortcut for something that you do regularly. Or making a basic template that can be easily manipulated for a type of job that you do repeatedly. After a period of focusing on just small daily improvements you'll not only be quicker, but more confident.
It's also important to remember that different companies and clients will have very different expectations when it comes to workflow and speed. The variable that you're not thinking about is quality. Something that has helped me enormously time and again is what's known as the 'pick any two' model. Wikipedia has a more detailed description but the basic idea is that out of three criteria - quality, time and cost - only two can be implemented at the expense of the third. So I would imagine that in the local print shop the focus was on providing a fast service at a competitive price - hence the quality of the work is the least important aspect. Not that it's not important, but it is of far less importance than the other two.
For example, imagine the print shop are asked for some business cards. No point in trying to win a design award, they just use a template and some stock icons, it's done quickly (Cheap + Fast = NOT Good).
Similarly the below diagram was made in a couple of minutes because I'm not getting paid and it only needs to be basic / functional.
I do not recommend discussing this model with a client / employer, or indeed using it as an excuse for doing poor work. But as a way of figuring out what the expected outcome of a job is it's quite helpful.
Of course, in the real world every client will want and expect all three - high quality work that's done in a flash and costs well below industry standard. The job of a designer is to figure out which areas to focus most on while also managing expectations. I have found that every design job I do incorporates this balancing act to some extent.