Resistors

There's not a lot to say here. We tend to do place these in logical groups, soldering each group and trimming the leads before moving on to the next group, but you could just as easily place them all at once (either bending the leads or using masking tape to keep them in place) and then solder them in one go. We prefer doing them in groups because it means the leads are less likely to get in your way...

As with all the components, aim to have it flush with the board (to minimise additional lead length) and if you can, try to have it nice and central between the holes (we'll admit to being pretty obsessive about that part, but don't worry too much about it).

Ceramic capacitors

Sometimes our suppliers send us ceramics where the leads have a wider footprint than the body, so in that case you'll want to gently straighten out the leads (we recommend a pair of needle-nose pliers for this job). Again, we like to solder these in groups, and try to get them as flush with the board as possible - you might need to gently pull them from the back-side of the board before soldering to get them snugly into place.

Button 

The button is pretty simple, and the one we supply neatly holds itself in place while you solder it so you don't need to worry about it having short leads. Simply push the button into the holes (don't worry, it only fits the right way) and solder it in. Be sure to use the edge of your soldering tip here to ensure the leg is heated along with the pad and the solder should just slide into place. 

IC sockets

These should be pretty easy too. A bit of masking tape is your friend here, we tend to do a strip across the RAM, ROM and MFP , then do the CPU and glue logic with another strip or two, depending on width. If your iron is the right temperature it doesn't take long to get each leg and pad to flow temperature, and you'll probably find a nice rhythm by the time you've done a few so although there are a lot of legs, it doesn't take too long.

We like to start by soldering the opposite corner pins, and checking the socket is straight before doing the rest. If it's moved, you can just re-do the corners.

Crystals

Again, we usually put a bit of masking tape over each crystal to hold it in place. Bending the leads works too, but don't bend them too much, and we do find that the crystals tend to move around a bit when soldering if just using bent leads, hence the tape. The crystals we supply are pretty hardy, but try not to get them too hot during soldering - if a joint isn't happening on the first try, let it cool a bit and then have another go.

LEDs

The main thing to watch with these is that you get the polarity right. The silkscreen has one flat side for each LED - this is the side where the short leg should go (if using LEDs we supply, the body of the LED has a matching flat spot, as do most standard 5mm LEDs).

LEDs 1 and 4 should be green, and 2 and 3 should be red. We don't recommend using other colours - you might need to adjust the value of some of the resistors if you want to do that.

We usually use a bit of masking tape to hold the LEDs in place, and take a moment to double check they're standing straight before you solder them - it's super annoying when you turn the board over to find that one of them has leaned over to the side somehow while you were soldering it...

Pin headers

The pin headers take a little more heat than most of the other components, but not much. You'll probably find a nice rhythm, just as you did for the IC sockets. 

We use masking tape here too, and again double check - the headers are prone to leaning, just like the LEDs.

A useful trick for the small headers (the two and four pin power and UART connectors) is to push the long-side pins through your masking tape, then stick it to the board with the short pins through the holes, ready to solder. We find this makes them easier to place properly and helps keep them straight.