Granny Square Scarf and Bag - free crochet pattern

For the scarf:  
I have made one basic granny squares (size to your choice) and continued to crochet rows, back and forth,  on one side only.  Then make a second square and sew it into place at the other end.
You can use up all your leftover bits of double-knitting yarn. 
Use a crochet hook to comfortably fit the yarn you're using - sizing isn't really crucial.
Two granny squares (or more) will also make a lovely bag -

(it may need to be lined though.)

Basic Granny Square
First round:
1 – Make a slip knot
2 – Chain 5
3 – Insert hook into 1 chain to make a circle. Connect with a slip stitch.
4 – Chain 2

5 – Double crochet in circle 2 times (first chain 2 counts as a double crochet)

6 – Chain
7 – 3 double in circle
8 - Chain 2

9 – 3 double crochet in circle

10 – Chain 2
11 – 3 double crochet in circle
12 – Chain 2 connect to top of first chain 2 with a slip stitch.
(First round completed) (You can changed colors here if desired)

Second round:
1 – Chain 2 turn work
2 – 2 double crochet – chain 2 – 3 double crochet ((corner cluster made)
3 – Chain 1 (this is one side of square)
4 – 3 double crochet – chain 2 – 3 double crochet (next corner cluster made)
5 – Chain 1 (next side)
6 – 3 double crochet – chain 2 – 3 double crochet (3td corner cluster made)
7 – Chain 1 (side again)
8 – 3 double crochet – chain 2 – 3 double crochet (4 th corner cluster completed)
9 – Chain 1 – connect with slip stitch to the top of first chain 2 (Second round is completed)

Third round:  you can make as many rounds as you wish your square to be working the same stitches.Repeat second round adding a cluster in the middle of each side row, with every additional round you make.

Always remember corners take a chain 2 and sides take a chain 1 for each space.

I have taken these instructions from here - there are pictures too if you need them.
Another lovely link