For anyone unfamiliar with the term, dead bug construction is where you put the integrated circuits upside down (like a dead bug) and solder wires and other components directly to their leads. Here are some photos and discussion:
http://dangerousprototypes.com/blog/2012/11/15/fine-pitch-bg...
I don't put photos of my prototypes on the Internet, but this is how it, more or less, looks like (only I use board with holes):
http://dangerousprototypes.com/blog/2012/10/24/who-says-bga-...
It doesn't cost a lot more of effort to solder a single SMT chip this way. I already solder everything else to the board anyway so cutting couple pieces of wire to tack them one by one does cost maybe couple additional minutes for a small size chip, and then I can go to working on the rest of the prototype.
Worst case, I use dead bug technique for a non standard component I don't have adapter for.
For large projects I might be splitting the problem into multiple separate functions and have a prototype of each function separately, later to integrate all to a single board.
For example, I am currently working on a controller that will control a heater, pump and couple of valves based on input from a bunch of very sensitive temperature sensor. I have two separate boards one for temperature measurement and one for 1kW of AC through bunch of relays, triacs, SCRs and so on. Each relay, triac and SCR is mounted on its own generic small boards (something like this: https://pl.mouser.com/ProductDetail/Chip-Quik/PA0185?qs=gjT6...), soldered in turn onto larger generic board (for example https://pl.mouser.com/ProductDetail/BusBoard-Prototype-Syste...).
All these are hooked up to a Nucleo board where I develop my software.
Once I have working prototype it makes no sense to spend time trying to make a half-assed board. I would very much prefer to design much better looking, much tighter tolerances board based on tolerances accepted by the PCB manufacturer and wait for it for couple of days.
If I really needed to work on the circuit in the meantime I still have the prototype. While waiting for a nice shiny board I can still working on software, find bugs, etc.