FIrst thing to note is that nothing is truly unlimited. Some things just have limits you haven't hit yet.
There are tools that let you rent out hashpower, but personally I like to know what I'm mining.
The next easiest method is to go to a service like WhatToMine and dial in your system specs. Most of the coins there are pretty developed.
The method with the highest potential profit is speculative mining. This is where you mine newly created cryptocurrencies that aren't yet well known. You want to find something that has a low network hashrate and a good potential to eventually be profitable. Not that in this case profit can be really hard to predict since you don't know what the price will be and often the coin isn't yet on any exchanges so you can't easily cheack the current value of what you mined. You also run the risk of one of these lesser known miners carrying a virus. FInding these gems often requires digging through Bitcointalk announcements and exploring various Discord and Telegram groups.
Actually mining is pretty simple.
- Download the miner from the project's Github page
- Find a mining pool for the project if possible. It will smooth out the block rewards.
- You'll also need a wallet. For projects you don't care too much about web wallets are probably fine. I don't recommend mining directly to an exchange address.
- Look up the suggested launch options and figure out what flags you need for your GPU(s). Absolutely critical is if the miner has a CUDA flag that you enable it for Nvidia GPUs.
- Then you unzip the miner, mark as executable if needed and run it. I recommend running it in a tmux instance.
- FInally you'll want to sell stuff. Exchanges are usually most convenient but they are not all created equal. Be diligent and don't get scammed. You can also sell P2P but you need to be extra careful to not get scammed.
Don't mine on your CPU, it isn't worth it.
Personally I think ASICs are only justified on very large projects like Bitcoin or for a project that you really want to support even if it's unprofitable.
I personally am currently mining Ubiq but it's up to you to do the research and figure out what you want to mine.