Until I make enough to afford one of those poker tools, I've been sort of disciplining myself by concentrating on how people bet even when I'm not in a hand, and I usually can type down a couple decent notes when some hands get shown down. It sometimes gets boring just watching, but it is handy to know if somebody is betting really small because they're weak or because they have the nuts.

The only time I use time as a tell is when somebody instantly checks (they likely used a button and probably fold to anything) or they take a long time against a big bet to them (the longer they take, the weaker their hand probably is). This is less important than the above though.

Even though it may not matter too much, I pause a couple seconds even if I instantly know what I'm going to do, just because it's a habit of mine in live games.