I use the systems of free trials (not trails).
But every time I do, I note in my diary the week when I need to get around to cancelling - and spend sometime before that finding out HOW to cancel.
I love Audible for my audio books, but find them very expensive. Audible charges £7.99 per month, which I think is outrageous. This gives one credit each month to purchase a book for 'free'.
Audible often make offer of three months at £3.99 (which is about correct), so I sign up for that , note in my diary when toi cancel, then usually within a week or so of cancelling find I can take up a further three month offer.....and so son and so forth. Does need to be a little organised, but well worth it.