All 8 Uses

however
in
Confessions of a Shopaholic
(Auto-generated)

By the time I sit down in front of the National Lottery, however, I've forgotten all about them.†
Chpt 4

however = a word used to connect contrasting ideas as when using though, in spite of that, in contrast, nevertheless, etc.
As I round the corner, however, the smile gradually slips, and I sit heavily down on a bench.†
Chpt 9
Luckily, however, they're so bowled over that I'm making all this effort on their behalf, they don't seem to care which newspaper I'm writing for.†
Chpt 17 *
However much fun it would be—it wouldn't be fair or honest to go.
Chpt 23 *

however = regardless of how
However, this press conference is restricted to the subject of the new Pension Series.†
Chpt 8
However, to my relief, Saturday arrives and I haven't heard a word from Tarquin.†
Chpt 9
Once I get on the tube, I'll open them both and I'll read them, however unpleasant they may be.†
Chpt 10
So whatever your query, however big or small, please call in for Rebecca Bloomwood's advice, on 0333 4567.†
Chpt 22

Definitions:

(1) (however as in: However, complications may...)
though (or another expression that connects contrasting ideas)

Based on idea 1 we might not expect idea 2, but this is a way of saying that even though idea 1 exists, we still have idea 2. Synonyms include in spite of that, despite that, nevertheless, nonetheless, on the other hand, in contrast and but.
(2) (however as in: However much she tried...)
to whatever degree (regardless of how much; or whatever unspecified amount)
(3) (however as in: However you do it, get it done!)
in whatever way
(4) (meaning too rare to warrant focus)
Much more rarely (and arguably incorrectly), however can be used to intensify the word how, as when one says "However did you find her?" Grammarians would suggest using two words for that usage: "How ever did you find her?"