To my mind the single most important piece of kit you must have on a boat is a compass. With a compass alone you can find your way broadly in the right direction. I have been caught a couple of times in a haar which took an otherwise bright and enjoyable day and turned it into a dark mystery. Using a compass alone you can at least be sure that you are heading towards land or away from a nasty obstacle.
However, that is the most basic thing a compass can be used for, it gets much more exciting and the joy is that you can practice all the methods on dry land, in your lunch hour even, as long as you don't mind people staring at your odd behaviour.
Most of us should have at some point in your lives taken a couple of bearings, drawn lines on a map and pinpointed your location. It is almost the same principle on a boat but with one significant change - you are moving! So, you should know your speed and direction, those of us that sail naked know that you really only have to know your hull speed in good wind (6 knots for example). You will with practice get pretty accurate at guessing your speed and it is worth practising, perhaps as a fun game during those long hours on the helm.
So, armed with your speed and direction you can assess your compass sighting strategy (I bet you didn't even think a strategy would be required until I mentioned it), objects directly in front or behind you are best for the first sighting. The reason is that they don't move very much. Once you have taken your sighting you can then draw the first line on the chart with a degree of relaxation - it isn't going to change very much over the next few minutes and that gives you time to find a pencil that isn't broken, sharpen it, find the straight edge/chartplotter and draw a line. Then redraw the line because you got it wrong. Let us not pretend that all these things are automatic yet and it is one thing doing it in the comfort of your local pub and quite another while you are being thrown about like a dog toy.
Great, first line drawn, now for your second one. This time we are going to take a bearing from an object off the side of the boat, it will move much more quickly, however since you have just rehearsed the process from the forward/aft bearing you should be pretty quick at this stage.
Two lines cross on the chart - that is where you are. It is indeed a "fix". You can draw a circle round it and put a dot in the middle. If possible you should try a third line - this eliminates the chance that you have misidentified an object, taking a bearing from the wrong chunk of real estate.
Where I live this works really well however if you are lucky enough to live somewhere like Canada you will find your lines really don't mark where you are. Why? Simple, true north (your chart) and magnetic north (compass) are not necessarily the same thing. Where I live it is only a couple of degrees out, in bits of Canada is can be 45 degrees or more out. It does make me wonder how the sailors from a few centuries ago managed it, really impressive and quite remarkable. We stand on their shoulders and should not forget their incredible achievements.
On your chart you will see some magnetic variance information, there are various mnemonics to help out like CADET, but you should be able to think it through yourself from first principles. The information on the chart also contains a bit of information and a date - so even if it is an old chart you should be able to work out the variance and crack on.
It is pretty much essential you have a hand bearing compass for this work and from my experience you tend to get what you pay for. A NATO approved compass is an excellent tool on land but is pretty rubbish on the water. Plasimo make an irritatingly good handbearing compass at a reasonable price.
Almost all the yachts I have been on have at least one of these, they are very effective, relatively cheap and portable. I am aware of other compasses on the market but in my part of the world I have only come across these ones. If someone want's to recommend other brands please feel free in the comments below.
I'm really skimming over the bones of compass work but the main message I wanted to get across is the importance of thinking about your sightings, slow moving stuff first (usually in the direction of travel or as near as possible), draw a line, then your fast moving stuff to get your fix. Practise at home, take a walk with a map and rehearse the skills until they are automatic. Once day you will thank yourself for the effort.
