I think there is no one fix as there are many variables. I find my machine likes finer threads best and tends to snarl more when I use thicker threads (such as general purpose polyester used in garment making).
Whenever possible use your straight stitch plate as there's simply less space for threads and fabric to be pushed down and therefore snarl.
Make sure you have long thread tails top and bottom. Put the needle as far down as it will go before starting to sew. You then have the longest length of thread available to the machine which means it can just start the stitching without having to 'grab' more thread - which tends to encourage nesting.
Hold onto the thread tails for the first few stitches. You can immediately tell if the threads have bunched as one will be very short and pulled out of your hand - and the sewing will not commence smoothly.