To be sure there is NO wrong way to build your models.
It's best to find a method that works best for your style of modeling.
Some folks are very detailed oriented, some just want to get it together and fly. I've seen some young folks slap a model together with white glue and fly it the same afternoon.
If your looking to create a decent finish on your models there are a couple different ways to go about it. all ending with the same fine finish.
Marks 10 steps are the Basic norm. but as with most things there are other ways to increase the production time while lessening the required steps. but these require trade offs in the way some things are done in some areas.
Personally I always completely construct all but the finest details before ever adding a drop of anything to the model. I haven't bothered with puddy fillers in decades. perferring to use primers as the filler on all but the very worst body seams or open balsa. For the vast majority of my models they are sprayed directly with the cheapest primers I can lay my hands on. fins are and major features are all applied with fillets and any add-ons attached. than the entire model is given 3 wet coats of primer. allowing about 5 minutes between coats. after the 3rd coat is applied the model is set aside to dry for about an hour or two at the most. then sanded with 120, 240 and 360 dry sandpaper until i'm happy with the smoothness or a reach paper or raw wood. If further filling is required I repeat the 3 coat and sanding steps until I have a completely sanded babies butt smooth model.
At this point a first coat of flat White is sparyed and inspected for those teeny tiny imperfections that only show up when sighting along the body held up in front of a strong light. If none are found it's on the the first gloss color coat, if something shows up another single primer coat usually removes these tiny flaws. it's on to the color coats, minimum two coats of whatever its the base color. allow these to dry in accordance with the lable directions. mask and knife any second color breaks and apply these color(s) as desired. Immediately removing all tape as soon as the color has had a chance to tack up. set the model aside to completely dry. Generally over night. at this point I'll wet sand the paint dam lines using a grey ultrafine Scotchbrite pad and plenty of water, being sure to keep it away for any unpainted or raw cardboard areas. Allow the model to completely dry and check for unforseen goofs like fingernail imprints are that stray dog hair, or piece of dust. Using Finessit-II or Perfect-it-III any of these minor surface defects are removed. Decals are applied and two coat of Nu-finish or a single coat of Future are applied to complete the model.
MUCH longer to type then do