Watch the RiffSolo 5 online guitar lesson by Matthieu Brandt from Jump Blues
Moving up and down the neck is easy, when you start playing a standard riff with your index finger on the tonic.
In the key of F you can cover almost the whole length of the neck. It is important to keep your eye on where the tonic in a blues progression are.
Find the tonic and the standard riffs around them can help you find a spot for your solo. These "sliding" standard riffs can help you move from one position to the other.