After the tutorials, play about 7 bot games which will get you to level 10. From here, you will get smite if you're a jungle main and get to do your own runes. While leveling up, you'll get to choose from several champions which one you'd want. I normally choose the highest cost champion in the case I would buy them in the future. Otherwise, get the champions that you normally play so you don't have to buy them.

Make sure you unlock enough champions through capsules so that you can play draft mode. You'll almost always get your role. You can solo queue normals up until maybe 10 games, which will then get progressively harder to carry. Make sure to find a party of about 2 other people or more with the same MMR. Some things you can do are to add players that performed in your previous games and play with them since they are also around the same MMR as you. Edit: Apparently, MMR doesn't affect your placements anymore, so you don't have to try hard every game.

There is a website called whatismymmr.com where you can see a rough estimate of where you stand in the normals "rankings". If you are win streaking a lot early, you'll be able to get to an above average normal standing (around 2,000). Try to get to around 2,400 or higher. Some advice is that for every loss you have, try to get 3 wins to recover from it, but you don't have to if your MMR is already high. Don't queue with people with a lot lower MMR because it will decrease your own MMR and can stunt it.

It's recommended that you find a competent duo for placements first. The goal is to get at least S2. You can get S3 but you won't be allowed to drop a game, otherwise you'll end in G4. At S2, you can drop about 2-3 games to get into G3 where you can then promote twice into G1. Getting into G4 isn't the end of the world, but you'll have to play an extra tier, which means your MMR will get a lot higher than your rank. The goal is to get a higher rank with the lowest amount of games so your MMR doesn't skyrocket while your actual rank is still low. Otherwise, you'll have to play more versus strong players. The highest you can start is S2 for NA and S1 for EUW. If you are in G3 near the end of your placements, keep dodging to the point where when you win the next one, you don't promote to G2. Otherwise, you will have to play G2 out to get to G1 whereas you can promote twice if you stay in G3 with one win away from promoting.

Dodging is really important, especially in placements, which is where you get the most LP. Don't be afraid to dodge because the first game is only -3 LP. After that, I would not consider dodging because -10 can definitely take a toll. Lobbies that have more than 3 griefers or hardstucks are definitely worth to dodge. As long as you have 3 players (including yourself) that are smurfs or high winrates, then you should play it out. Every first dodge is about 6 minutes, then if you don't play a game after the dodge, it is 30 minutes, and after that is 12 hours. Otherwise, it's 6 minutes after a game. Every 16 hours, the dodge timer resets, so you can dodge twice a day with both being -3 LP. Make sure you have multiple accounts so you just have to dodge once on each account.

The most you can gain in gold smurf queue is +28 and -5. In plat, I believe the most is +33 and -5, but I have yet to see. If you are getting 1 or 2 less, it doesn't really matter but you don't get free dodges without having to play extra games. For example, if I get +28 and dodge, I will be sitting at 25 LP and only need 3 more games to promote. However, if you are getting +25 or +26, then dodging means you would be at 98/99 LP at most and would have to play another game to promote.

I've tested that you can skip promos as long as you have around 3 divisions of MMR above your rank (ie. Gold 1 with Plat 2 MMR). I had high Plat 3 MMR and I was still able to skip but just to be cautious you should have around Plat 2 MMR.

For the players that get into G4 and don't want to play 3 tiers to promote, you can remake 2 games after you promote twice to G2. There is no MMR loss for remaking, which means it's better than playing another tier. The penalties for remaking twice in a row are -3 LP for your next two games, -2 LP for the third game, and Low Priority Queue (5 minute wait for 5 games). So when you promote twice into G2, you start with 1 LP, which is good because the first remake will only cause you to lose 1 LP since it counts as a loss and cannot go below 0. Only dodging makes your LP become negative if you don't have enough. For the second remake, it will cause you to demote to G3, so you will be at 75 LP. If you are getting high LP gains (+28) then you will have exactly +25 LP to promote twice into Gold 1 becauses of the LP penalty. You'll also have 1 LP since you are promoting twice. I believe this also works in Plat but it's harder since you are approaching Diamond MMR.

So far I've only queued late at night and early in the morning (12:00 - 5:00 AM PST). The queues are very long (10-15 minutes) so you often end up with hardstucks at your actual MMR. If those players are formidable and you have a good duo, then you play it out. Otherwise, dodge those players as there is a chance the enemy team can be full of smurfs. Queuing as support is also not that bad if you queue in the afternoon and early night, since you will tend to get teams of smurfs while the enemy support is usually not a smurf. In long queue times, queue as your main role since queuing as support with long queue times will get you hardstucks in your main role.

I think duoing is fine as long as both of you are on your main roles. Soloing is doable if you know that you can 1v9. The only problem is that sometimes you may not have enough players that are smurfs or good, which results in dodging. Make sure you have at least 3 smurfs including yourself. If you are doing with someone low elo like around Silver or Bronze, it will not affect your placements or LP gains. I'm not sure about after placements though.

It's best to play early game champions to accelerate the game to a faster tempo since most of the other players can't keep up. Ignore dragons unless there are no opportunities to take advantage of. Take both herald if you can and keep applying pressure to every player on the enemy team. Don't rely too much on your teammates because they are quite unpredictable. Make sure you use herald to get first tower and at least two charges for efficiency. Note: this is for games that should be easy (early normals/ranked)

If you can play more than 1 role and there's short queue times, you can queue as fill as long as you one of those roles you play aren't mid. This way, there's a better chance a smurf will be playing in your other role.

Does the normals MMR have the same effect on flex placements? No

Does duoing with lower MMR lower your own MMR? It lowers your the MMR you play in, but I don't think it lowers your actual MMR.

Does duoing with lower MMR still let you promote twice? How much LP do I get? You should still be able to promote twice. Your LP gains and losses should also be still be normal.

Can I dodge 14 times to demote? No, you will reach -100 LP eventually and cannot go further than that.