Whether it is difficult or not depends on a number of factors. I agree with Domingo that supply and demand is a big factor. Native English speakers appear to be in very high demand, which is good for me, but on the other hand, I get many requests from people I have no interest in conversing with - you teach me English, I'll teach you (insert some random language). This is hardly an enticement for me, as I am only interested in learning Japanese. As for under 25's having the edge - I disagree. I set my language partner requirements as female, native Japanese-speaker, middle aged or older. I have half a dozen regular language partners and I have to knock back at least two new requests a month as I just don't have time for anymore. The other factor is time-zones. Fortunately for me, Japan and Australia are only 1 hour different, so arranging a mutually convenient time is simple. I don't know how helpful any of that is to you - but don't give up, keep trying. Good luck.