No, that is the rule of thumb. Set it to what you expect to possibly be used. In most cases, I'll actually match the amount of swap to memory in case of core dumps, etc.
SWAP should rarely be used, if it is being used and starts thrashing, then it's usually time you need more memory. SWAP is kind of the like the insurance policy, it's there just in case.
Your free output indicates no swap is being used, so your in good standing.