Great to have such a healthy load of tips here. I have a couple questions if I can.
So first or all I'm gonna jump into this saw debate. I have a Presch dovetailsaw (what it was listed as on Amazon) and it seems very thick for a decent fine cut. It's also got teeth more like a normal jobsite saw and not fine at all so it feels like it's impossible to get a good cut started. It also feels clunky and the handle off to the side thing is not my favourite. I know its for changing over sides when you need it but it just doesn't feel good to use for accurate fine cutting at all. Other than that it's alright but not fit for begginers dovetailing perhaps. I am definitely going to get myself the Suizan 265mm Kataba. £25 and the blade is a lot thinner and finer than the Presch me thinks.
The next thing is my dovetail marker (also Amazon). I am looking at dovetails people have done and it looks like there is a much bigger angle on them. You can make them any size you want right? 1:8 being the most common for hardwood in England? Anyway. I'm wondering now if I'm using it correctly. Am I supposed to use both the 'inside' and 'outside' markers for one joint? I am a bit confuddled with it. Just because of the angles I have seen on other dovetails look a lot more noticeable than mine.
So am I even using the marker correctly?
The saw does look horrendous. To be able to make an accurate and straight cut you need to be able to control the saw. My preference is a pistol grip western saw. What you will find is after cutting a number of dovetails you develope a muscle memory and can repeatedly cut at the same angle each time. I cut my tails first and cut all the same sides of a row of tails then twist my wrist to get the other angle and cut the other sides. I find the pistol grip to be much better for a repeated registration in the hand. But many people prefer the round gents saw type handle and that's fine too.
For the marking out I think you are having some struggles. The angles are important but not critical. The difference is generally for hardwood vs softwood. A typical hardwood tail will be 1 in 7 and a typical softwood tail would be 1 in 6. That said as long as the tail is not too extreme pretty much any angle will work that gives an ecstatic that you are happy, 1 in 8 is a good option that will work with everything. There is no need to have exactly the same angle on both sides of the tail. If I'm doing a "fancy" joint where the joint is a part of the design look then I will lay them out accurately to get even spacing using dividers and a dovetail marker to get consistent angles.
Here is an example where the joint is an integral part of the design so these were laid out accurately
If I'm just making a box to hold some tools then I only mark the depth I need to cut (the thickness of the pin board) using a marking gauge. Then pencil a line across the tops of the tails, on the width of the board, with a square so that I have a guide to cutting straight. I don't mark down the side of the tail at all and simply angle the saw to what feels right then cut down to the gauge line.
I might be wrong but I think you are placing your dovetail gauge on the wood and drawing both edges of a tail directly from the gauge without moving it. The dovetail gauge is realy just a specialised square and you should use it in the same way. Slide it up to the point where you want to mark the angle then move it to the next place. I mark all one angle first then go back and mark the other side of the tails using the oppoisite angle on the gauge. After that you don't use it again. The pins are marked directly from the tails after the tails are cut. With the exception of the gauge line for depth I use a pencil to mark out the tails. The pins are traced from the tails using a knife.
Just a comment, one that might get some debate, is that cutting the tails first lets you saw the less critical angled cut first. If you don't cut the angle consistently on each tail it doesn't matter. As long as the cut is at right angles to the board it is fine. When you cut the pins you have the marking knife line to show you exactly what angle you need to cut across the board to match the tails it will fit with and the saw cut is simply perpendicular to the top of the board. Cutting with a saw perpendicular to a board edge is much easier than trying to cut to a desired angle. Grab yourself a board and use a square to scribe a few lines accross the edge of the board then use your dove tail gauge to continue a few of the lines down the board like you are marking tails. Then use the square to mark a few of them at 90 degrees like you would do for pins. Have at them with your saw and I think you will find that you will be able to cut more accurately to the 90 degree lines than the angled lines. For me that is the main reason for Tails first. Tails first is also a litte easir to deal with when marking the pins from the tails compared to the tails from the pins. You will find that some people will angle the board in a vice so that the tail cut lines are straight up and down and may be something you want to try but for me it is an extra step i don't use.
Edit: Corrected my softwood tail angle. My dyslexia for the better of me and i looked at my guge upside down. I use 1:6 not 1:9
