The trick for success is to use the method that works best for you. We can all sit and talk until the cows come home about every pro and con of each sort of orbit/transfer/rendezvous technique there is. But if you manage to get your Kerbals to the Mun, by getting a slingshot off Minmus via the sun, (apart from being worshipped as some form of sorceror) it will make you feel warm inside and people will probably try your method of doing things. Tutorials help with KSP, and there are many fantastic ones out there. They only help to a certain extent though, sure if you wanted to you could copy everything you have seen in guides and either fail or succeed each time. Take what you think works best for you out of each thing you watch, read or listen to. Apply it to your own designs, if it works for you, keep it, if not then bin it. That's the beauty of this game. "X" person designed this rocket. I like "this, this and this but, definitely not that". Pretty much all the tutorials and guides out there give you an excellent example of what to aim for. They will give you the basic design for a craft, orbital techniques and all the trimmings. Who's to say that you can't combine twenty of the things you have seen and then launch yourself on a figure eight orbit between Kearth and the Mun? The only reason it's not been mentioned before is because nobody (I did a quick search of the forums so please feel free to correct me) has done it TL;DR All of the tutorials and guides you see are correct, it's all down to personal preference, technique for doing things or what colour hat you are wearing on the day.