Good questions. Well, for me I think the first thing to do is to find a teacher that truly teaches enlightenment is possible in this lifetime. I know a lot of Tibetans will say that, but the way they treat students does not always reflect that nor does the community of westerners that surround him/her.
If you find someone like that, most likely their teaching of the vajrayana will be much more down to earth and direct. At this point in time, I say look for a "good enough" situation because Tibetan Buddhism is a lot further behind in creating a Western form than the Insight and Zen traditions (not that they're perfect).
As for me, I've studied with Namkhai Norbu and the way he teaches is on par with what I'm suggesting, and I find the practices direct. A lot of formality is either thrown out the window or simply recontextualized according to what really matters in practice, and as such, much of the culture and dogma is softened, sometimes removed. As for the practices, Vajrayana uses some interesting practices, as you might know

The whole body is engaged. Because of that, it might be easy to interpret a certain practice as being completely bizarre and cultural, but actually it would probably be just as strange in a Western form. That's just the style of practice.
Ngondro - well, this is a mixed bag. I think if it's done right, it's very powerful and helpful. If it's done in this idea of "I can't get enlightened", no good, I say. Also, it seems like certain versions of ngondro are more effective than others. Namkhai Norbu doesn't have students do them, but in his training model, you essentially do a version of that, but possibly a more effective way, though I can't firmly claim that.