This is how I recently collimated my telescope. The design is not "standard", but the principles are the same: 1.) Ensure that the primary mirror is reflecting its focus point down the center of the tube. 2.) Then place the secondary mirror in the center of the tube. 3.) Test the image of a bright background to get concentric reflections of the "primary-secondary-eyepiece" train.

Use an "extension" of 1.25 diameter basin pipe (visit your local hardware store's plumbing section) in the eyepiece-holder to get your eye farther away (yet centered) from the secondary reflection. The farther your eye is from the telescope, the better/more accurate your sightings will be.

You can make a "dummy" eyepiece (from wood or an old high-power eyepiece like you get with those Tasco-type reflectors). This ensures that your eye is centered in the eyepiece position when you finalize your collimation.