When the calf starts eating calf creep from your hand-held bucket, it is time to wean them.  We take them completely away and put them in a small corral. We go out two to three times a day with a little cob or three-way grain in the bucket.  They will come running.  While they are eating, put the halter rope around their neck and halter them up.  They should be very used to this by now.
We work with the calves in pairs.  This takes two people.  Start leading them (or pulling on them) around the corral.  We lead them holding the halter rope up close to their head and making sure their head is held up.  If you allow their heads to go down, they are difficult to handle.  We lead them standing on their left side with their halter rope in the right hand and the tail in the left hand.  That way you can use your whole body to help block them from turning left and your right hand to keep from veering right.  Sometimes we use the bucket in the left hand to get them to follow us.  When they get the idea of following you, we take them out of the corral and start leading them around the place.  They love finding new green grass.  We start leading them around our country roads in pairs, introducing them to everything new.  When something new appears (cars, animals, trash cans, signs, etc)  take a tighter grip and be prepared to have them try to turn and run.  Circle them until they calm down.  We operate on pressure and release.  When they are cooperating, the lead rope is relaxed.  When they are not, the rope is tight and their heads are being held high.

We back our trailer up close to the corral, halter them up and put their buckets in the trailer.  It only takes a time or two of tugging to get them to jump in the trailer for their grain and the trailer lesson is accomplished.

If you find that when they leave their corral, they just want to get back with the rest of the herd, it is the easiest to just load them up and drive away from your place and practice in a different area.  They are such a herd animal, that you can't accomplish much around the herd. You will find that in a strange surrounding that they have really bonded with you rather than the herd.