Dear Eliza,
I use a Singer machine, but what I do is first thread the top needle with about 6" of thread hanging down, then I lay the bobbin in, thread about 6" extended and laying to the left, keeping the bobbin case OPEN.
Next, holding the end of the needle thread so it doesn't get pulled into the machine I manually turn the wheel to go down and around and this picks up the bobbin thread. Then I close the bobbin case.
Now, both treads are out the back ready for sewing. Before I begin sewing I extend 6" of the top thread and hold it with my left hand to the back till the machine starts.
-Susan