My interest in electronics goes back to the days of playing with batteries and bulbs and that was sometime before I was ten.  My early attempts at soldering were not pretty and I have a few solder scars on my hands to prove it.  The advent of cheap microcontrollers has been a wonderful progression.  For a few pounds I can design circuits that would have required several boards of discrete logic.  Operations like debouncing button presses that normally require a separate chip can be taken care of in software.
Some circuits I design and some I just build.  Quite often it's a mixture of the two - taking an existing circuit design and modifying it to suit my needs.  Unless the circuit is very simple (in which case I just knock it up on stripboard), I design and build a printed circuit board.  I'm currently using the Eagle schematic capture and PCB design software from CadSoft.  It comes in versions for Windows, Macs and Linux.  I'm using the Linux version.  They also do a Freeware version that, although limited, will suffice for a lot of people.

To make my own PCBs, I print out the final board design at a high dpi setting in just black and white onto high resolution inkjet paper.  Then I cut out the board outline from the paper and spray it with WD40.  This makes the paper go quite transparent.  Then I take a copper clad board that has been coated with a photo-resist layer (I've tried making my own but I haven't had any success), align the paper with it (making sure I've got it the right way round otherwise the result will be a mirror image - been there, done that!) and lay the two on the glass bed of my UV light box.  It takes about ten minutes to get the board properly exposed.  Then I soak the board in dilute Sodium Hydroxide to remove the photo-resist layer that wasn't blocked by the black ink of the paper printout.  Next, I etch the board using Sodium Persulphate (which is much nicer to use than Ferric Chloride) in a deep tray with a fish tank bubbler to keep the solution moving.  When etched, the board is rinsed in water and dried and then exposed in the UV light box for another ten minutes so that the subsequent soaking in Sodium Hydroxide will remove the rest of the photo-resist.  That's followed by a final rinse in water and then, when dry, a quick burst with a polishing block.  I can get a PCB made in about an hour on a good day.  Having said that, the board still needs all the holes drilled and that really does take hours.  One of my more recent projects was to find a solution to that problem and there is detailed coverage of that below.

First up, here's an early surface mount PCB project:  the USBkey.

PIC microcontrollers are great but you need to be able to program them, so:  the PIC Programmer.

I hate drilling all the holes in PCBs.  Why not build a Computer Numerical Control (CNC) drilling machine: the Drillcon 100.

Aaron asked me for an optical (TOSLINK) S/PDIF decoder for his Playstation2:  happy to oblige.

Another suggestion from Aaron.  An iButton controlled lock using a PIC chip:  the iButtonLock.

Bit of a work in progress this one - avoid losing your laptop with the invisible radio Laptop Leash.

Laser stenciler cutting head for the Drillcon 100.

More projects soon.