Est. 1998 — 27 years of woodworking knowledge
Turning Ellis's poll on its head
Bill Tindall, E.Tn.
What "Internet tip" have you tried that was a waste of money or otherwise a failure? I'll start it off with six:
Stabilizing washers on a table saw blade
ripping wide boards and regluing to result in more stable panels
alternating growth rings in panels to result in more stable panels
Trying a Stanely 55 to make molding
"piston fit" drawers
Purchasing any of the several doweling jigs I have bought.
Re: Turning Ellis's poll on its head
Jim DeLaney, Austintown, Ohio
I'll go along with all of those, except for the Stanley 55 comment. It actually works pretty well once it's set up right. Takes a lot of fiddling, though.
Confession: I usually just skip the 55 and use the router table.
Re: Turning Ellis's poll on its head
Ralph Lipeles
I'm with you on the 55 plane. Some years back I bought a vintage oak side by side cabinet to restore. It was a real bargain because the top and bottom horizontal pieces of the swing out door frame were missing. I used my Stanley 55 plane to to make the contours for the outside contour and the contour that goes by the glass. The pieces came out pretty good.
Bad advice
Ellis Walentine
The internet is full of advice that is questionable. Though not in line with the *good* information you may have found here, I'll be glad to compile a file of bad stuff as well.
Ellis
Re: Bad advice
William Duffield
Snort! With a few notable exceptions, the Internet is based on the promulgation of bad advise. 
Re: Bad advice
Joe shelton
Lots of sources exist solely to obtain those 'clicks'.
7+
Mark Mandell - Gone Round In New Jersey
That set of "4-way" clamps
and at least half a dozen other gizmoes that I threw away or gave to woodworkers I didn't like that I've succeeded in forgetting.
All of those...
David Weaver
..and
* any fussy sharpening system that relies on expensive stones. This is one that will never go away as there are a few aggressive pushers of such things. It's not just the expense, but that usually the process is a wrong turn for anyone wanting to become skilled at sharpening
* ditto on the washers and stabilizers - even though I already said all of those
* lining up panels not necessarily by growth rings but the insistence that it's important that the planed direction is the same on panels or bench tops, etc. This is a complete waste of time and potentially aesthetically counterproductive
* constant pushing of generalized gadgets and jigs for things that can be done well by marking/hand/eye
* super thin saw blades as a rule rather than a want
* insistence of a certain hardness for sawplates (fast sharpening is more important)
* jointing every time you sharpen a saw
* large router jigs to flatten slabs/tables
* (not universal on this forum) insistence that basic joints on guitars must be made entirely with power tools and jigs to imitate machines (a better fit in key areas is usually gotten quickly by hand).
* "glue line ripping" or any mechanized substitute for getting a fine panel glue (it's not hard by hand and the result is always good rather than hit or miss)
* super thick or super hard plane blades and component as a necessity to do neat work (another detriment rather than improvement).
* really any tip that tries to solve hand woodworking issues with power tools and imitates the hand methods, or the converse.
Re: 7+
Bill Tindall, E.Tn.
I'm trying to not remember similar follies.