Let's take a look at the events that brought two of New York's heroes together....
Reflections Of An Old Meeting
This issue is a follow up to Amazing Spider-Man Annual #2 (October, 1965), which featured the first appearance of the villain, Xandu. Here, Xandu has hypnotized Spider-Man to break into the Doctor's home to steal the Crystal of Kadavarus, so that Xandu can re-energize his Wand of Watoomb (that Strange drained in the Annual). Through Xandu's magic, Dr. Strange appears hostile to Spider-Man, and the two fight when Stephen tries to stop him, but Spidey does find the gem to take to Xandu. Xandu wants his full mystic might back to sale the woman he loved, Melinda, whom he had put into a coma while learning magic. Spidey and Doc face Xandu in his home dimension, with Strange casting a spell to switch their powers (which aren't quite working right), to enable the heroes to defeat Xandu, casting his Wand into another dimension. Dr. Strange lives up to his profession, examining Melinda, to find she is not in a deathlike coma, but a coma-like death, which she cannot be returned from.
Doctor Says I Need More Iron
This story is part of a multi-issue arc, with Iron Man being Spider-Man's partner for issues #48, #49 and #51 (though Doc makes appearances in the last two...). In this issue, Spidey is recruiting Doctor Strange for help with the Wraith, whom he believes may be a supernatural menace. The Iron Man team-ups and most of this issue are covered here, but this tale is worth a mention for Spidey's visit to Dr. Strange's Sanctum Sanctorum...and that Doc trusts Spidey enough that his house wouldn't react to him as a threat.
Deal Me InMs. Marvel) bumps into Wong, Dr. Strange's manservant, while shopping, dumping his goods to the ground. While helping him pick them up, Wong receives a telepathic distress call from the Doctor, and heads to his aid (with Peter Parker witnessing this at the end, and changing to his Spider-Man clothes and going along). At Strange's home, the Orb of Agamatto (a mystic possession of the Doctor's) has begun an attack at Strange and Clea, with Clea injured and the magical defenses of the Doctor's home down, both Spider-Man and the newly re-costumed Ms. Marvel show up, offering help. Dr. Strange, along with Spider-Man and Ms. Marvel, head to New Orleans to get help for Clea, from Marie LaVeau, the Witch-Queen of New Orleans. They decide that Clea was under attack from the Silver Dagger, an old foe of Stephen's, and Dr. Strange must go into the Orb to save Clea, and sends his astral form, leaving his body behind, under the protection of Spider-Man and Ms. Marvel. Silver Dagger attacks in the real world, as Strange had been the target all along, and Silver Dagger looks to take his revenge while Stephen searches for his love.
Meetings Get A Little Hairy
with the Human Torch, in Marvel Team-Up #35 (July, 1975) and with Spidey, Quasar, the Scarlet Witch and more in Marvel Team-Up Annual #5 (1982), which have been covered before, as well as working with the Scarlet Witch alone in Marvel Team-Up #125 (January, 1983), and as a part of the Defenders in Marvel Team-Up #111 and #112 (November and December, 1981). That's the nice thing about Dr. Strange, he always has patience for dealing with other heroes!