I think it's great how many project tutorials there are out there for custom made camera and guitar straps, since people with cameras or guitars tend to be creative types, and anyone with a DSLR camera knows that the straps that come with them are boring advertisements of the manufacturer.  So, make your own!  This first one is by Lier on ikat bag blog, and she made it all from scratch (as opposed to using the readymade strap) using vinyl for the ends and dog collars for the strappy parts.  I love the Orla Kiely fabric!

The following camera straps use the original strap in one way or another, so if you have a plain strap already you can make it your own.  Made by Petchy has a tutorial for this camera strap slipcover - she says in the intro: "if I make a slipcover, I can make loads of different ones and change the look of my strap to fit my mood!"  Brilliant!

Design*Sponge shows us how to make their version of a strap cover:



And Cluck Cluck Sew has another cover tutorial, this one using different fabrics on front and back:



Make It and Love It blog has a tutorial for this scrappy camera strap, which is sewn to the original strap to be permanent, and uses pieces of different fabrics:



Lacey of this life of mine blog did a tutorial for a custom ribbon strap:



A few years ago I made my own crazy custom strap, knitting a strip for the front with scrap yarns and sewing it to some durable fabric for the back, with fusible interfacing between the layers.  My method of attaching it to the camera is not exactly the most secure (I'm always having to tighten it and be careful) so I've never done a tutorial, but here's a picture just for fun:



For a different kind of camera strap project, amyles on instructables shows us how to copy the design of the expensive R-Strap device.



And lastly for the cameras, mattyfu.com has a how-to for a wrist strap for smaller cameras, using a recycled strap from a thrift store bag:



Moving on to guitars, you could start out by reading this ehow page on making a strap from scratch, but if you'd rather use a preexisting strap material, a belt is perfect!  Bleachedaneurysm has an instructable for making an old belt guitar strap...



And Elizabeth Seward on Planet Green did another belt guitar strap how-to:



For a more DIY look, TimAnderson has an instructable for this instant guitar strap which is simple and secure:



If you're a fiber lover, Vickie Howell has a pattern on knitty for this knit strap (you could leave out the fuzz if it's not your thing):



And then Lion Brand has free patterns for both knit and crochet felted guitar straps.  This one was knit by azurerocket on flickr:



Don't forget about duct tape, always a favorite DIY material!  Dman2295 has an instructable for this duct tape guitar strap:



Lisaisab on craftster made this gorgeous scrap leather mandolin strap:



If you'd rather embellish a plain strap rather than make a new one (and this goes for camera straps too, or any other kind) try cross stitch!  This space invaders strap was stitched in "retro-fabulous colors" by the domestic scientist:



And now for a couple totally different straps, to round out this roundup.  Jenny Ryan did a tutorial on Craft blog for a yoga mat strap:



Invisiblelight366 on instructables shows how to make an iPod/iPhone wrist strap for way cheaper than similar ones on the market (and you could totally customize it with some color/patterned fabric if you want):



Hope this inspired you to get crafty and show your creative individuality with your camera, guitar, or anything else with a strap!  Happy crafting!