“Let me be honest with you: I tend to judge a fly tier’s skills on his or her ability to make a nice head on a fly. Simple as that.”
and i’ll be just as honest in saying that i completely agree and share the same point of view as Martin Joergensen.
ugly, sloppy, materials-or-varnish-cramming-the-hookeye heads are just that; ugly and sloppy. i’ll up that in sarcastically stating that tiers who display this despicable ugliness should be… 
somewhat joking aside*, Martin’s recent article on GlobalFlyFisher brings up a whole busload of great points on how to finish off a fly whilst bearing in mind that that finish is often influenced by how the fly was started in the first place:
“Even the first few thread wraps can have an influence on the appearance of the head on a fly. Start in the wrong place and the proportions of your fly are screwed. Tie in the rib too far ahead before adding the body, before putting on a wing and a hackle, and there’s no room for the head. Too far back, and you have bare shank that either needs to be covered or will simply remain bare.
Too thick a wing, too dense a hackle, too lousy a technique, and there will be demand for many wraps to cover the misery, leading to a head way larger than needed – and way larger than what looks good.”
for lots and lots more thoughts on fly construction, examples and concrete tips, be sure to click the pic above to access Martin’s article. enjoy !
* you’re right, i’m turning into a grumpy old bastard and even if its a conscious and wilful decision and that messy fly heads usually catch just as many fish as nice and pretty-headed flies… my point isn’t so much about being a grump but of encouraging tiers to up their game, develop their technique and bring it to another level. hopefully.