Mm, your endings for 'best endings' are debatable. So I guess just play the way you want? There's no real 'best ending' in my opinion in any of the games.
The main quest, regardless of your inquisitors actions is always going to be and end the same, regardless of class so play the class you like the look of. Some Companions might only want to romance a certain race, so if that's an issue for you ROMANCE SPOILER. I think that's the only one?
I will say this, Qunari have less armour available to them, especially helms. So if that's an issue for you, don't pick Qunari.
I'd say these are a great set of top 10 tips to new players:
This is an important one: Leave the Hinterlands! As with any RPG it’s completely understandable if you want to ignore the main story and just do other things for a while. We have done so as well, but Dragon Age: Inquisition presents possibly the first time when you’re actually encouraged to play through the main story. At least, for a while… just, you’ll know when it’s safe to do side quests but until then try to ignore them for the most part, okay? Seriously. You can always come back to them another time since there’s no point-of-no-return in this game, reportedly. Thank us later.
Some quests require you to have a certain amount of ‘Power’ and this effectively requires you to go out and do some side-questing. Don’t stress too much about it, for the most part the ‘Power’ rating won’t even be an issue and if you really have to, this is where it’s okay to head back to the Hinterlands, complete a few quests and then return to the War Room. Remember that you can gain ‘Power’ by doing literally any side quest. Your best bets are rifts, camps and requisition orders since they’re all quick and easy.
Picking the best party members is key for your experience, and really helps you avoid much trouble. Since this game offers no dedicated healer, the role of the mage is significantly less important here although having someone around to cast Barrier is still recommended. Ideally you want one rogue, one warrior and one mage at the very least. Then you’re free to pick the last one as you please, or to taste depending on which character you like. In previous games two rogues worked best but here you’re welcome to have two warriors or two mages as you please.
When picking your party members, do also leave some consideration for combinations. For example, a rogue might be able to put characters to sleep and then say a mage has a spell that causes extra damage to enemies that are asleep. Read the skills you level up and note what combinations are possible, to maximise the effectiveness of your party, and if your current party isn’t working well together then don’t be afraid to switch out.
On the subject of levelling skills, if you find yourself running out of stamina/mana a lot then don’t be silly and skill more actives, rather skill passives because those don’t require any stamina/mana and just work automatically. If there aren’t any passives left then upgrade the actives you already have. Then once you’ve got a few levels and your stamina/mana isn’t as much of a problem, consider more active skills.
It’s important to collect every possible herb you stumble across, and you might consider levelling one of Leliana’s Inquisition perks that allows you to harvest a bit more per herb. Early on, you’re going to aim for upgrading those potions. At least one level of healing upgrade to health potions, and as many as possible to regeneration potions. The regeneration potion is your single greatest asset in this game, during and after fights. Treat it with love and respect.
How does one upgrade potions? Easy, silly! Explore your map. Specifically your base. Explore all of it, and be sure you speak to everyone regularly. Select every conversation option and ensure there’s nothing left before moving on. Yes it will take long (literally hours) but it’ll be worth it, and you’ll also find that your base tends to have a lot of extra stuff, such as armour and weapon crafting, potions upgrading and more. Explore!
During fights it’s important that you maintain situational awareness throughout. You need to know what’s going on. You don’t necessarily need to live your life one tactical view at a time but you do need to pay attention to such things as health bars, stamina/mana bars and who is getting attacked by what. Character placement is important. Pause if you have to, go into that tactical mode, ensure always that the tank (warrior) is the one taking all the hits while your ranged teammates are further back.
Learn how to prioritise your targets. Focus your fire on either the weaker but more devastating enemies (mages and demons) or anything else that would allow you an easier time. Sometimes it’s better to just let your party handle the big enemy while you pick off the rest. Other times you’re going to want to kite your enemies and draw their attacks away from weaker teammates.
To that extent, it’s important for you to familiarise yourself with the ‘tactics’ and ‘behaviour’ settings in the Character Record, for all your party members. If you spend a little time in there configuring them, it allows you to basically never need tactical mode because they’ll always do exactly what you want them to, meaning you can relax a bit more during fights.