Learn to take shortcuts. This might take a little practice, but it's worth it. For instance, in puzzles that talk about butterflies, they have some pretty long and obnoxious words. These can slow you down. A lot of the time, the four or five long words in one category will each start with a different letter or syllable.
When you read a clue that says - The Lepidopterous who collects Hesperidae doesn't like chocolate - let your brain take a shortcut. If you have to read the whole thing, read it as - The Lep who collects Hesp doesn't like choc -. You can make this even shorter. The word Lepidopterous doesn't help us to solve any clues. You can skip the word, and learn to spot only the ones that really matter. So the clue becomes - Hesp...doesn't...choc.
The same thing works for phone numbers and license plates. Don't read the whole thing, only enough to identify the clue. UAJ-461 might be the only plate that starts with U. If there's more than one that begins that way, take it only as far as you need to. UAJ-461 and UHU-893 can be separated by the first 2 letters. Skip the rest, it'll only bog you down in unnecessary details.
Finally, if you find yourself getting confused, say it out loud. It solidifies the clue in your mind. I mutter to myself a lot when I'm solving, and it helps. I say things like "Hesp is chocolate" and "You-who (UHU pronounced) isn't first". These things have greatly reduced my solving time, and I make a lot less mistakes now.