Originally posted by SaiyanBeyondGod
You'll have to get these trophies on your own:
Gatekeeper - Join the College of Winterhold
Taking care of Business - Join the Thieves Guild
Snake Tongue - Successfully persuade, bribe, and intimidate
Skill Master - Get a skill to 100
Explorer - Discover 100 Locations
Expert - Reach level 25
Master - Reach level 50
There's an exploit you can use to legitimately obtain Skill Master, Expert, Master, and the earlier level trophies as well in the very first mission of the game. Whoever you choose to follow in that tutorial mission - the Imperial or the Stormcloak - you'll eventually get to a point where you need to stealth past a bear. Your NPC companion will hold up and follow your lead. Crank the difficulty up to Legendary, crouch down and go behind them until the sneak icon appears (a closed eye), draw your weapon and start whacking them. Make sure you don't kill them. Keep shuffling your feet back and forth a bit. The way the mission is scripted, the NPC will not turn hostile. When the NPC's health gets too low, stop hitting them long enough for their health to recover. Then start hitting them again.
Because the difficulty is cranked up, both your sneak skill and your one-handed skill will rise dramatically and your level will shoot up too. It happens faster at lower levels, and takes more skill points per level as you get up there, but there's absolutely nothing stopping you from maxing out your entire skill tree and capping your level in that first mission, except your own boredom. Once either sneak or one-handed hits 100, Skill Master will pop, and the last level trophy pops at 50. If it gets boring for you, you can obviously take breaks. Should take about an hour.
For the other trophies you mention, you can check any of the saves here and see if the relevant active question that says "join the..." is still marked active and if so, fast travel to wherever and join. I thought one of the other Skyrim save sets had trophies for these and definitely for Snake Tongue but maybe I'm wrong.