1. Don't ask questions that are hard to explain over phone. For instance I was asked if I've used Lambdas in C# and I said, "Yes, extensively.", next question was. "Explain to me what a Lambda is.". I gave the textbook definition for it, and he was expecting more, so I simply said "It's hard to explain lambdas, I can show you some source code I've written and that way I'll be able to explain it better.". I thought that was it and that I would be 'screened-out', but I was moved to the next round of on-site interviews!

2. Do ask questions about how the candidate has used the technologies that the job requires, and ask them to explain how they designed and implemented their most recent solution, and where they used what technology, and how. After initial answer, drill deep into areas that are important for the job posted, and from the answers, you can get a fairly good assessment of whether the candidate should be moved to the next stage of the process.

3. After passing the tech phone screen, I've received and completed 3 take-home coding exercises (1 each from 3 different companies), and in 1 of those companies, I was subject to white (water-) boarding exercises on site in addition to the take home test. The white boarding seldom goes well because of the environment and nature of the whole thing.

I found the take home exercises to be better than on-site white-boarding because the former is closer to how a future employee would work, than the latter.

Also, how a candidate does on algorithm and data structure questions is a false positive (or negative) because these can be practiced, rehearsed, perfected and hence gamed. Coding exercises, or specific question on the candidate's most recent project, on the other hand, cannot be 'gamed' and even if it was, you could tell from listening to the response, or from reading the code...

Hope this helps!