Forget the clock - you have plenty of time.
5 minutes is ages - hold your breath for 5 minutes to see how long it is.
I'm sorry Thud but the advice about staying within 5 minutes of your
opponents clock is not sound. You are placing the clock first and giving
the lad something to worry about.
Position first - clock second.
If the position demands you jump into the think tank - then off you go.
And stay in till your are sure you have the best move.
Don't come back here on Monday morning posting.
"I lost all my games but I was 15 minutes ahead of everyone on my clock!"
If your opponent is in major Time Trouble do not speed up.
Play the board not the clock.
The wise guys will NOT resign. They will let their clock run down to
see if you are going to get caught in the blitz trap. Don't.
Don't write down the moves of your game - but after the game
record them. (you should record every game - even friendlies).
You can have some great fun in allegro's.
Here is one of my games from Grangemouth 1990(ish).
A nice opening trap which I have caught a few people with on here.
(Look - if ever I'm Black and I leave my e-pawn hanging - don't take it),
I remember the young lad saying he was told to play 2.Bc4 to
avoid my Latvian. (it was a team event - I was in the same team as
GM Jonathan Parker. I remember him frowning at a few of my moves.)
I'm Black - can't recall the lads name - he is most likely a top player now.
Good Luck mate and if you see a sacrifice but cannot work out if it's
good or bad. Play it.