  We improve the efficiency of sawtooth-wave-adiabatic-passage (SWAP) cooling
for strontium atoms in three dimensions and combine it with standard
narrow-line laser cooling. With this technique, we create strontium
magneto-optical traps with $6\times 10^7$ bosonic $^{88}$Sr ($1\times 10^7$
fermionic $^{87}$Sr) atoms at phase-space densities of $2\times 10^{-3}$
($1.4\times 10^{-4}$). Our method is simple to implement and is faster and more
robust than traditional cooling methods.
