Music stores can be intimidating. You’re walking into an environment where all the staff there have heard every cliche’d song butchered a million times, and where it can sometimes be hard to get some attention in order to be assisted in choosing your new guitar, pedal, pick, strap, pickup, gadget or wotzit. Now, it would be an exaggeration to say that Wayne’s World shaped my entire development as a guitar dude, but it certainly introduced me to the concept of the May I Help You Riff: a riff or lick that you can play in order to instantly attract the attention of the staff and maybe even gather a bit of a crowd around yourself to gape in awe at your shred skills. Here are a few that have served me well over the years. 
String Zips

This is a trick you can sometimes hear coming out of Jeff Beck and Eddie Van Halen. The concept is simple: pick a note, slide super-quickly until you get to a specific fret, then let you and pick the open string a few times. Easy! You can mess around with this technique a bit more by not doing the open string bit – just let that note sound by itself when you lift your finger off the neck, and then move to the next zip.
Open String Jack Butler Stuff

This lick is based on tricks Steve Vai used as Jack Butler in the film Crossroads (one of our Great Guitar Movie Scenes, by the way). It’s essentially an open-string hammer-on/pull-off lick which incorporates open strings and string skipping. Part of what makes it sound so interesting is the contrast between sequential and repeated notes. The first three notes are a relatively fair distance apart from each other, and the fourth is a repetition of the one before it, but performed on a different string. This is a great way to build up finger independence  and to force yourself to play right on the fingertips, otherwise you could accidentally wipe out your notes. There’s a certain classic rock vibe to this lick, and you can use it for The Who-style synth-a-like patterns, Jimmy Page-esque “Heartbreaker” solo ripoffs and much more. Try moving to different frets to see what happens.
Different Finger, Same Note
Here’s an interesting approach to getting some different textures happening out of the same note. Looking for a way to make a repeated note sound less, well, repeated, without having to change pitch? Use a different finger to fret the note each time you play it. This forces you to play teensy tiny grace notes and ghost notes as your fingers slide up to or down to the target fret. Try throwing this into an otherwise low-tempo melody for some real weirdness. It can sometimes create a sort of digital stutter type effect which I think a lot of players might dig as they start to explore ways of applying guitar to dubstep. There isn’t really a good way to tab this – it’d just look like a whole bunch of repeats of a single note with an instruction like ‘add more ghost notes than the Haunted Mansion.’
Muted Hammer-ons

This is a neat trick for imparting some percussive chop to a riff, section or solo. While typically a player will perform a hammer-on lick without palm muting, heavy muting combined with a repetitive hammer on lick and chunky attack on the initial note of the sequence can create a really wild, percussive feel. This works especially well in minor pentatonic riffs and solos.

What are your favorite May I Help You Riffs? Do you have your own? A favorite lick from a famous artist?