It's a good idea to change passwords often. Some sites even force a password change after a period of time or after a certain number of logins.
The problem is that it's tough to think up passwords that are tough to crack but easy enough to remember and use over a number of devices such a desktop, laptop, smartphone, tablet (and probably many other variants of devices being invented over the next few years). One easy-to-use method was to use ASCII codes to generate symbols that look like English characters, such as Σ for the letter E. However, laptops and smartphones generally don't have keyboards that can generate such characters and attaching an external keyboard is just blech.
With a little ingenuity, though, you CAN generate a password that's easy to remember but tougher to crack than the usual passwords, and which can be used across devices.
The trick is to use a simple technique that lets us associate characters with letters of the alphabet.
For example, can you pronounce the following word? D@vvg.
If you read that as Dawg, you get the way in which you can generate a password that you can remember but which a hacker can't really crack that easily. That word actually contains a capital d, an "at the rate of" symbol, two v's and a g. Yet you can easily remember it as Dawg.
Let's see how to apply this technique to create a password. Let's say you met an interested person named Abigail recently and she's been on your mind enough to make you use her name as a password. So is she @b1Ga1L or aB!g@i| or A81g@il? The human mind can clearly see these as Abigail but computers, being mere number crunchers, can't. So software-driven password hacking systems, even if directed by human hackers who know something of you, can't really crack such passwords.
Some symbols that can be used as letters are:
1 for i or I
2 for s or S
! for i or l
@ for a
# for h or H
$ for s
^ for n
^^ for m
& for S ( for C
/ for l
vv for w
VV for W
Mix up the letters and symbols, use random lower case and upper case letters and your pet's name becomes an unforgettable and hard-to-crack password!