That sounds more like a silkspan job than tissue.  Perhaps there's a difference in dialect when you fly over the pond?  Note also that folks here have made statements about "silkspan" that sound more like tissue to me -- so make sure you're getting what you expect.

At any rate, for either tissue or silkspan you first dope the surface with at least a couple of coats of dope, more is more work, smoother, and heavier.

TISSUE

For real tissue, you want to use Esaki tissue.  You may be happy with the 'economy' tissue that Built Right models sells, but unless you're an absolute tightwad you'll be much happier with Esaki.  If you use anything other than Esaki make a test panel first and try it out.

Over open structure, apply the tissue dry, adhering it with dope, shiny side out.  Pay attention to grain -- decent tissue (like Esaki) has a definite grain, and you want that grain running lengthwise on your parts.  Generally the grain is along the long direction of the sheet, but you can check by test ripping the sheet -- there'll be a direction that it 'likes' ripping -- that's the grain direction.  If the dope just seems to soak into the wood without sticking down the tissue, you didn't use enough on the framework.  Over open structures with simple curves you can apply the tissue dry as well.  Over solid wood in compound curves, with Esaki, you can carefully apply dampened pieces of tissue; the dampening will help the tissue conform to the curves, and Esaki tissue will take this sort of treatment without tearing too readily.  If you're covering open structure with compound curves (like a stick-and-tissue rubber model), use strips of tissue -- sometimes one per bay if things are highly curved -- between the stringers.

Note that you want to get it mostly smooth at this point -- you can stand a few minor wrinkles, but a wrinkle that's 'minor' for Ultracoat is HUGE for tissue.  Decent tissue does shrink, but not a whole lot.

Once the tissue is on and the dope is dry, dampen the tissue.  The old way to do this was to spritz with water.  I've found that either spritzing with 70% rubbing alcohol (outside!) or just rubbing the plane down with a cotton ball soaked with same works better, as it gives you better control of the amount of water.  Let it dry overnight, and the tissue (you did use Esaki, didn't you?) should be taught.  Then dope.  You shouldn't need sealer, which makes me think that the author was using silkspan.

SILKSPAN

I'm told that Sig silkspan is best.  I've never bought anything but Sig, and I haven't bought Silkspan for decades -- so I'm not sure what's best to get these days (I'd try Sig, and hope they have it in stock).  Real silkspan is basically paper made with fairly long silk fibers.  So it doesn't weaken much in water, and it doesn't shrink much from dry.  It also doesn't have the tight, shiny surface that Esaki tissue does -- but it's stronger.

Prep the framework as for tissue, perhaps being a bit more lavish with the dope.  Put the silkspan on damp.  Pay attention to grain, just like tissue.  Cut a piece to size, dip it in water, wring it out, drape it on, gently stretch it over the area you want it to go, and stick it on with dope.  You'll find that when it's wet it's quite willing to follow compound curvatures.  As with tissue, you want to get it mostly smooth at this point -- leave any big wrinkles now, and you'll never get them out later.  When you're done, let it dry and it should tighten up.

At this point I've always put on non-shrinking dope.  It'll loosen when you dope it (as will tissue), but it'll tighten up again when it dries.  Put on a couple of coats of just dope to seal the individual fibers.  You'll have a surface that (unlike tissue at this point) is still porous.  Now put on sanding sealer until the surface is as sealed as you want it to be -- you don't have to get it 100% for decent flying, but you sure do if you want to do a fancy paint job, and a porous surface isn't going to help keep things fuel proof.  Depending on how motivated you are you can gently sand between coats of sanding sealer -- you're trying to build up the sealer between the pores of the finish, any sanding sealer on the surface just contributes to weight and roughness.  Be very careful that you don't sand through the covering at the rib edges.  You can fix this with a patch of silkspan plus more clear and sealer, but it's a pain and takes lots of work to cover up the error.

When you have it to the point that it would have been right after finishing with Polyspan or Silkspun Coverite, then go ahead and squirt your automotive sealer.

I've used Polyspan, and I like it on old-timey RC airplanes pretending to be free flight.  I know folks here who say it works well on stunters, but I haven't asked the group what the whole "process" is -- i.e., what to use for primer, topcoat, etc.  For a nice, but not award-winning, finish, you can use Polyspan, rough side out, and Nelson's paint -- except that Nelson has suspended paint sales and is looking for someone to buy him out.

I can say that it is not like other iron-on coverings I've used.  Because it doesn't have adhesive, and because of the need to get all the wrinkles out before shrinking (so all you're doing with shrinking is taking up the slack, not getting rid of wrinkles), you have to approach it much more like tissue than like Ultra Coat.  OTOH, because it only sticks down where you've put adhesive, the process is much more controllable -- I always seem to hit a point in a Monocoat or Ultra Coat job where I have a big wad of covering material all stuck to itself, laughing at me.

Thanks Bill, I'll take note of your advice.. Phil