‘Tips on accuracy’ is the title of this thread; I assume there are many out there who'd love to improve their ‘accuracy’. Now I’m no ‘guru’ however; I did pick up, back in the day, some ‘tips’ which, IMO, provided great assistance. FWIW I shall mention some of the very earliest (those I can remember), which have now become ingrained habit.
The first was ‘use your eye’s boy’. I was not allowed to pick up a square or gauge until I had ‘looked’ – properly – at the piece. This came as part of preparing my own stock, from ‘rough’. To take a largish lump of timber and extract from it ‘joinery’ quality billets was part of my young life. Rip saw to length and thickness, minimise waste and still end up with the ‘best’ bits for the job. No mean feat; but then to plane them to two square faces, of equal thickness and to exact width and length was difficult. “Use your eyes boy, after your hand; then use the gauge ”. To arrive at the desired measurements, without ‘assistance’ was difficult – but after a while and many mistakes – I learned to ‘see’ the wood. A board which seemed flat to me became a thing with a ‘bump’ just off centre, after while I could judge that by backing off the plane blade a quarter turn and using one, two or even threes strokes, I could dispose of the villain spoiling my work. Thus I learned to count. This was a three stroke bump, or a two short and two long ‘bump’; thus I learned to sight for twist before reaching for the ‘winding sticks’ (only used on long stuff). To this day I ‘use my eyes’ for measurements (before setting a gauge) to confirm that which I suspected. I still estimate the number of plane strokes required – at the setting I’m using – mostly I get it within the mark – then use the finite ‘assistance’ to finalise.
It is the same with ‘square’ cutting; for example in dovetails. Learning ‘where’ to look instead of where you were is a knack, acquired y practice. Watch that Paul Sellars eyes when he is cutting anything – they are always focussed on where he wants to go, never on where he has been and most certainly not on the bit he’s cutting. “Use your eyes boy, the saw will follow”. Provided you do not have a death grip on the saw and are not ‘driving’ it, mostly you endup in the ball park. Rip sawing is a lovely thing to do, particularly if you have a good rip saw. But you don’t ‘need’ one. “Use your eyes boy” get the first half inch square then, gently, guide the saw along the desired path, keep straight by correcting while dropping your hand – just a little and let the saw do it’s work. Remembering the first stroke is the important one, unless you want a round corner because you let the saw ‘wobble’.
The last little ‘tip’ was delivered as part of a rollicking – I’d badgered a joint. “Why?” bellowed the master. I tried to explain – alas. “No mate” says he – “you were lazy and laid out that joint on the corner of bench, the thing was wobbling about everywhere; the light was bad and you used the wrong face – do it again – properly”. (Fined half crown).
Accuracy depends on ‘square’, application and practice. Remember your first dovetail? Mind you – you can still stuff ‘em up; and, them what claims perfection, (by hand) every time is stretching credibility – just a bit.
But, most importantly – do not measure your work against ‘masters’ – measure against you own progress. Last week you could not square off the end grain exactly – this week you managed it; do that four times and then accept that you can do it. With that knowledge comes confidence, accuracy follows – speed is simply a by product of your ‘knowing’ how to do the job. But; the ‘eyes’ have it methinks.
For what it’s worth, that is my two bob spent.