There are a few tutorials on the web that are for little man suspenders.
HERE is one that uses "Fashion Fit" clips that I couldn't find in my local stores.
HERE is another tutorial that uses dyed elastic, but that was a little too expensive for me.
I like the first tutorial, but I couldn't find affordable clips and mine needed to be all fabric. I grabbed some houndstooth that matches Brother's party stuff, a pair of thrifted suspenders and got to work.
(forgive the black and white pictures, but you really don't want to see my ironing board cover...blech)
For Brother (one year old) I made my fabric strips 24 inches long. For a toddler, I would go with 27; infant 21...if in doubt, measure baby and add 4-5 inches. Your width will depend on how wide your suspender clips are. My clip was a little less than and inch and a half.
Sew Right Sides Together to form a long tube. Turn tube of fabric right side out.
Press so the hem is in the middle...this will be the back of your suspender.
I used a thrifted pair of suspenders and cut the metal attachments off of the elastic.
Here is where it gets a bit complicated, and I hope that my pictures can explain it better. If not, take pictures of your intact suspenders to use as reference for how they go back together.
The part that lengthens the suspender is call the "SLIDE". (I didn't make that up) You will use a roll hem and sew the FRONT of the FABRIC with the BACK side of the SLIDE facing you.
Pull the suspender "CLIP" onto the strip of fabric with the clip facing the right side of fabric.
Pull the free end of the fabric through the slide. Now it looks like suspenders!
The second clip goes on the open end of the fabric. Sew it on just as you did the slide. Using a roll hem so you don't see the ratty end of the fabric.
REPEAT, because you need two straps silly!
Measure your child from front waist band to the back waist band, making sure you cross it in the back.
After you have that measurement, make sure both of your straps are even.
I tried them on Brother and found where they crossed well in the back. You could guess, but make sure the back clips are several inches apart, or they won't lay flat.
Sew a diamond shape where the straps overlap. You don't have to do a diamond either...the next time I'm thinking of doing straight lines all the way across or just doing a big "X". I will also be using iron on interfacing for the next pair. These worked great for what I was wanting, but I think they would be better with a little more umph!