Weathers getting a bit warmer here .. but I'll list the places on day basis..and the ones that you can do together
Ain Garziz, Ittin plains/oasis, Nabi Ayoub Tomb
Al Mughasail beach, maneer caves and blowhole. Al Fazeyan Beach ( requires 4x4 )
Wadi Darbat, Ayn Athum, Anti gravity point.
Taqa castle, Taqa cliff and beach and there's a wadi there too.
wadi saihalnoot Ain Razat Salalah Gardens Mall
Dahraiz beach and its coconut stalls and Al Husn Souq , Sultan Qaboos mosque.(for shopping)
caution google maps turn by turn navigation doesn't work in Oman so having another device or map would help!!