Personally, i just have footsloggers. And surprisingly, its worked well so far. I have no trukks, no warbuggies, nothing. Just footslogging boyz, and the Warboss and his Retinue. No special tricks. There are just way too many boyz to cause more then 1 mob to break before it hits their main line. Then, what the heck is he gonna do with all those slugga boyz running around causing problems? In so far, the people ive played against underestimate the mobility and effectiveness of my Orks because they are on foot. I was a little sketchy about it as well, and the Tau in particular scared me. But they couldnt thin out that many mobs before they hit the line. After that, the Suits and the Fire Teams just disappeared under a green tide one squad at a time.
Trukks im sure make it much easier, but i dont think its half as fun.