This is much easier than you think – simply take the presser foot off, drop the feed dogs and place your fabric in an embroidery hoop. Set your machine to a short wide zigzag if you want a satin stitch effect or leave it on a long straight stitch for 'drawing' designs. Move the fabric by hand instead of relying on the machine to do it for you.
Take it easy and use a specific leather needle. This technique should be as simple to stitch as a heavy weight cotton. Just remember that once the needle has punched through the leather it will leave a mark so make sure you know where you want to stitch before you start. You might find a Teflon foot helps the leather slide through smoothly.
Mixed media projects call for a marriage of fabric and paper. A sewing machine will give an extra element to these type of things. A sharp needle used with a slightly thicker top stitching thread will give the best result.
Yes, there's a reason your machine comes with a variety of different feet; it's to make your life easier. Although most of your stitching will use a simple straight stitch foot, it is worth checking up on what the other feet are designed for. Using the correct foot is as important as the right thread and optimum tension.
I don't recommend that you take your machine apart, but there are several simple things you can do to ensure it keeps running smoothly for as long as possible. Always put the dust cover back on when you've finished for the day and regularly remove the bobbin and race to get all the lint out with a soft brush. Open the side and brush the fluff from there, too before giving the moving parts a drop of fine oil. Once a year, unplug and turn the machine upside down in order to remove the bottom cover if you can. You'll be amazed at the amount of fibres that can gather around the gears; leave it too long and they will eventually jam up.