The planets are sticking close to the horizon during prime viewing hours for most of October, making them more of a challenge to see. After sunset on October evenings, look to the left of where the sun was to catch Mars (and maybe even Saturn) low on the horizon. Saturn is sinking and joining the sun, where it reaches conjunction toward the end of the month, but the Red Planet will stay just above the horizon for the rest of the year. On October 1, Mars will be in Libra, heading toward the claws of Scorpius.
The moon can guide you to some of the planets in mid-October. Try spotting Mercury on October 16 and 17. Mercury shines at magnitude -0.1, making it brighter than Mars, but its location closer to the sun leaves it in the sunset’s bright glow as the evening begins. On October 16, Mercury is just to the upper left of the slender crescent moon. On October 17, the moon is between Mercury (to the moon's lower right) and Mars (to the moon's upper left). On October 18, the crescent moon will lie to the upper left of magnitude 1.2 Mars, with the Red Planet’s reddish rival Antares (the Anti-Ares) shining a bit brighter at magnitude 1.0 just below Mars.