We make a big point out of being experienced and selling that fact, but what exactly does this buy you. That's hard question to answer quickly, but there are a couple of key examples that may shed some light on what we mean.
1. Using the newest, neatest, sexiest devices in a project is always a temptation, but if those devices are in short supply or are ONLY available from some small manufacturer, THAT'S A POOR CHOICE OF PARTS. We try - as often as possible - to specify parts that are "available". There are often many many ways to solve a problem .. the secret is finding the RIGHT way.
2. Boards MUST be designed with their ultimate manufacture in mind. Even so simple an idea as the size of the holes MUST be taken into account. A board that's going to be hand soldered uses a different size hole than one that's about to be machine soldered ! It's called DFM - Designing for Manufacturability - and we take it seriously.
3. A significant source of failure in electronic devices is mechanical failure. That is, the electronics themselves didn't fail, but something wiggled loose, or the board flexed and twisted until a trace cracked, or the connectors weren't adequately supported, and they eventually pulled away from the board. We make every reasonable attempt to minimize these sorts of "real world" sources of failure.
One of these real world situations occurs in the use of "vias" . Vias are holes in a circuit board that allow traces on one side of a printed circuit board to join up with traces on the other. Vias are a necessary evil in the design of a PCB, but they are also a common source of failure. ( The copper gets very thin right where the trace takes a right angle to go from top to bottom, or bottom to top. ) A good designer takes every effort to minimize their use.
The aforementioned "big guys" use zillion dollar software, and let the machines attempt to remove vias. But it turns out that via removal is one of those pattern recognition problems that machines still have a little trouble with. An experienced designer ( there's that word again ) can usually do a better job at this irritating fussy job than even the best software, if they care to. We care to.