Willem186
Shit I love my metronome so much, (GP5). You don't understand the importance of the humble click until you are faced with recording time. You will not produce music that is in time if you don't practice with one.
I had this problem just recently, I was recording at a home studio, it belongs to one of my mates, I could not nail the timing, I had to double track the left and right guitar parts with a friend, and I am not really happy with the result, its very slight, but it's noticeable by musicians, and it is not cool.
So the moral of the story is, without long-winded insightful banter, get a metronome, and get it now, if you don't have one, you have been warned....(insert evil laugh)
BMU
For rhythm playing, I've found the best practice is to record yourself doubling a part, to a click track. It just pinpoints any hidden sloppiness with excruciating, humbling clarity.