CPU + RAM friendliness

CPU-friendly
32- or 64-bit integers, SIMD
Sequential memory-hard functions
"Large" variable S-boxes
However, this prevents use of SIMD until AVX2 VSIB
Use of specialized instructions - e.g., AES-NI
CPU-unfriendly
Small S-boxes (variable or/and fixed) - waste machine word bits
Beware of bitslicing and byte permute instructions
Bit permutations
Such instructions are to appear in 2013 in non-SIMD form, though
Unusual transforms
e.g., integer addition with only partial carry (an adder with some holes punched)