Are you looking at written or spoken English ? In general it is rare for most speakers I think. I don't often shorten words while speaking anyway.

Right. You might want to look at a specific group of speakers who do this often. Some groups of young women do this more often, such as "def" for definitely or "tots" for totally, etc. you might find some data there.

I'm not sure what sites to suggest but maybe you could search for those words on forums or other sites and see if that helps to get you started.

I have to say I'm not sure exactly what it is either. Natalia, if you have a technical definition, please provide it. I'm just going with what makes sense to me, but that might not be exactly what you want for your research.

I think those would count, Cory. I'm not sure whether it still counts if it is lexicalized and widespread. For example, "ref" for "referree" or "pro" for "professional" is probably not a relevant example at this point. The ones you cited are probably relevant though. (I don't think "innit" would be, because that's just an alternative/fast pronunciation, not really missing the end.)

The examples you gave me is that’s exactly what I’m looking for. Thanks! But to make it clear, here you’ve got a definition and some examples of clippings.

clipping – a process denoting the subtraction of one or more syllables from a word.

Examples of different types of clipping:

fore-clipping: phone < telephone, burger < hamburger, plane < aeroplane
back-clipping: turps < turpentine, bike < bicycle, mike < microphone
mixed clipping: van < advantage, flu < influenza,  fridge < refrigerator
clipping compounds: sci-fi <science fiction, sitcom < situational comedy, biopic < biographical picture
o-clippings: limo < limousine, rhino < rhinoceros, aggro < aggressive, evo < evening
y-hypocoristics (typical of Australian English): barbie < barbecue, brekky < breakfast, leckie < lecture

Haha I'm a bit guilty of using 'totes'

Can someone explain a little more about what clipping is?  If I'm understanding by context, there's quite a few examples in British English, for example 'soz' for sorry, 'whatevs' might be another...  I don't know if 'innit' counts for 'isn't it', or 'bruv' for brother.

Thank you for the links! The examples you gave will be very useful:)