When I did the arm increases I used the make one (M1) method. Here's a brief description of the method.
If you want the stitch to slant to the right,
insert the left needle under the bar between the stitch just worked and the next stitch on the left-hand needle from the back.
Next, knit the stitch just created on the left needle as a normal knit stitch.
If you want the stitch to slant to the left,
insert the left hand needle under the bar from the front.
Next knit the stitch through the back loop.
Use your left index finger to manipulate the newly created stitch to ease the tension on it a little. It will make it easier to insert the right-hand needle into the stitch to knit it.
Sometimes a pattern will specify if you should use a M1R (right slanting) or a M1L (left slanting). If it doesn't, just think about where you are placing the increase and decide which way you would like it to slant. After all . . . it's your project!!
Speaking of projects . . . I guess it's time to start a new one! A friend and co-worker is looking through patterns . . . I hope she decides on one . . .
Until next time, keep your nose in a book or your fingers in fiber.