DS used to get colds alot as a baby (still does now as a toddler) - things we found helped:
- steam/warm bath - elevate cot head slightly
- when baby is older you can try karvol drop on muslin under cot too I think. We also used to suck bogies out of DS's nose with one of those suction devices when he was a little older (nostrils abit too small for them at 6 weeks).
He seemed to nap abit better sitting more upright in his bouncer when he was really bad with snuffles - may be worth a go.
We have a 12 day old baby and she already has snuffles - we bought a snot sucker and seems to sort the problem on the short term (its become part of the nappy changing routine) ours was £5 from mothercare.