Wall tile layout

[grifter]

Just wondering how the pros would tackle my issue. I'm tiling some kitchen wall area for my awkward mother-in-law and she has bought 75 each of three different shades of tile and 25 of a darker colour to break things up a bit. She wants them placed randomly with no pattern or repeat lines. Should I just mix all the tiles up and take them as they come? Any advice?
Thanks

 

[DAZB]

This may be useful :
http://www.iansharpe.com/random-tiling.php

 

[grifter]

Thanks for the link. Much appreciated