RC-ing for me is to stare at a particular point in the environment, such as a speck of dirt on the wall. If the world starts falling apart, you are dreaming, and then you immediately stop staring and reconstruct the world to whatever you like. If the world doesn't fall apart, you're probably not dreaming.

However, this method easily results in just stopping REM and making you lose consciousness. I'll try nose-plugging more often.

Another method I use is to read a book. Usually the text doesn't morph by themselves in my dreams, nor do they change by the second look, but I RC by looking at a word and intently focusing on it and telling the book to change that word. Sometimes I try willing the font to change.

You can also put your hand on the table and watch it sink through... in dreams that happens and more often than not the dream table gets wrecked...