1984 - The New Mutants #13 Cover by Bret Blevins

1988 - Anatomy of a Cover - The New Mutants #66 by Bret Blevins and Terry Austin

Magik by Bret Blevins

1989 - New Mutants #82 Original Art by Bret Blevins

Found these pieces over at: 

http://dchudson.blogspot.ca/2012/04/new-mutants-by-bret-blevins.html

1985 - Anatomy of a Cover - Incredible Hulk #310

By Bret Blevins and Al Williamson

Bret Blevins' Cloak & Dagger

From the collection of Edward Harris:

1988 - Storm by Bret Blevins

From Marvel Fanfare #37.

1983 - Crystar redesigns by Bret Blevins

Grabbed from Comics Feature #23:

1988 - Anatomy of a cover - New Mutants #69

http://www.coollinesartwork.com/GalleryPiece.asp?Piece=291898&ArtistId=1312&Details=1&From=Room

1987 - Anatomy of a cover - New Mutants #49

http://www.coollinesartwork.com/GalleryPiece.asp?Piece=291897&ArtistId=1312&Details=1&From=Room

1989 - Lost Magma story

The synopsis for New Mutants #81 from Marvel Age #79, read:

“What if the prince of your dreams turned out to be a nightmare? For Amara, that’s exactly what she faces – for the prince she’s being forced to marry is a vampire! Will the New Mutants be able to rescue her from an undead fate worse than death? Written by Louise Simonson, pencilled by Bret Blevins, and inked by Al Williamson.”

The following month in Marvel Age #80, the synopsis for New Mutants #82 read:

“Is Amara falling in love with the vampire she’s being forced to marry? Her change of heart makes matters worse for everyone! In fact, the New Mutants may not survive the latest challenge to the wedding! Written by Louise Simonson and pencilled by Rob Liefeld.”

That storyline never happened as New Mutants #81 was a fill-in and #82 continued Louise Simonson's telling of the New Mutants' return to Asagard. So there must have been some kind of delay with Rob Liefeld who didn't start on the New Mutants until #86 in 1990.

1984 - Incredible Hulk #300 unpublished cover

Tip of the hat to Ferran Delgado who found this on eBay, the unpublished cover to Incredible Hulk #300 by Bill Sienkiewicz.

And here's the published version by Bret Blevins.