Uni-Knot

Here’s a great knot for tying heavier line to swivels or baits. 

Run the tag end of the line through the eye of the hook, swivel, etc.
Place the tag end of the line along side the main line pointing back up the line.
Turn back the tag end towards the eye of the bait so you now have three sections of line running along side each other.
Wrap the tag end of the line around the main line and the tag end that you first placed along side the main line when the tag was pointed away from the bait.
Each time you make a wrap around the two lines you should be running the tag end between the first two sections of line and the third section of tag line that you created when you doubled back the tag end to create the third parallel line. 
The wraps start at the bait and work there way back up the two lines away from the bait, five times.
Moisten and pull tight.
Use your finger nails to pull the wraps down snug against the eye of the bait. 
Pull on the tag and main lines again to ensure the knot is tight and then cut off the tag end leaving about ¼ inch.