You may additionally want to bear in mind that people might be calling you from their cellphones, and a long message can use up someone’s valuable cellphone minutes. Some voicemail systems have the option of pressing a key like the pound key to immediately start recording a message; you may want to consider the funny or long message only if you have this option available to callers. Another point of consideration when recording an answering machine greeting is who is likely to call. If you’re job hunting, for instance, you may want to drop the funny salutation for a while, and use a more standard and businesslike greeting, unless you’re applying for jobs as a comic. Is Amazon actually giving you the best price? This little known plugin reveals the answer. Some answering machines utilize cassette tapes.
Your voicemail message should ideally answer all of the following requirements: Brief -- nothing bores callers as much (or makes them hang up as often) as long voicemail messages; Informative -- if it's your professional voicemail, say your name, business, and if necessary, department. Let your callers know when to expect a return call

Going hand in hand with preparing and thinking your message thoroughly before calling, there’s now the need for you to speak slowly. This doesn’t mean talking very slow as if you’re talking to a child to get your message across. Rather, it simply means enunciating every word carefully and practicing the right spacing, so your listener is able to understand you.
Much, much simpler method: Hold phone up to the source and play track while in “custom” and “record.” Some degradation of quality of course. Life full of trade offs.