How do I design my ships so the design gets updated with completed research?

It remembers your designs from previous games, so those designs will show up as soon as you have the technology.

However, each game usually has a varying technology path, so the above is usually not viable and you just have to keep designing each game.

Personally i don't usually bother designing new ships for each and every technology improvement. I wait until i have several technological improvements saved up, then do a new design. And depending on the situation in the game, i may not be building updated ships at all.... often i am building virtually 'blank' hulls which stand guard at strategic locations and can be upgraded in any emergency. Often no emergency comes in that location, so i have saved a bunch of money on maintenance costs.

This is not what I was looking for. I want to build an "outline" of a ship design, or a template, like what is done for the core ships.

Well its the same for the core ships, they wont show up until you have the technology.

Or are you talking about the 'blank' hull designs that show up when you select 'new design' and you have to chose which hull size you will use?

You can add your own hull designs in here no problem..... i mean the first thing i do when i build a new ship in terms of the 'visual' no active components, is to 'save template', then it shows up with the other blank hull designs every time, every game.

I believe what you are after is creating a ship set, which allows the game to use your hulls the same way it uses the default hulls, updating designs with each tech advance.  That is a modding function.  I have not tried it.  There are modding guides out there for that.  A google search got me to several, but I have no idea which ones to point you to.  

Erischild, you may be closer to what I am asking for, but maybe not quite. I remember all through the Beta that there was supposed to be a way to create ship templates that were used to automatically create ship designs that automatically had the latest technology. You created a skeleton design that automatically got the latest engines, weapons, and armor, and gave the template a name that the game added "MK0", "MK1", (or something similar), ... to it.  I guess you could call this a ship set, but it doesn't sound that much like modding (where you provide a complete set of factions, their characteristics, and their ships (or ship templates)).

I have been trying to discover how this (ship templates) is done ever since the Beta and have had no success.

You can't find it because it doesn't exist.  It was one of many beta ideas that never made it into the game. 

Currently the only way to do what you want is to either modify the existing ship sets or create a completely new one.  Both have to be done outside the game.  There is a thread in the modding section that covers how to do it, but you'll probably need to search for it.  It was called something along the lines of "How to create a ship style in 15 minutes".

Thanks.