It is impossible to mine bitcoin directly now these days with anything other than an ASIC. This does not mean however that you cannot mine totally. There are alt coins you can mine, but there is also a novel solution from Nicehash. This is where your GPU mines the most profitable alt coin at that moment, and auto exchanges it for Bitcoin.
It is simply to use, you can simply visit Nicehash here. From there, you can download the nicehash miner. It will benchmark your GPU and CPU, and from there you simply hit the green button to mine as shown below, after adding your wallet address.
Once you begin mining, it will show you daily estimated earnings for that worker. Note that if you have multiple rigs, it will only show that rig, you can view your stats page to see the total earnings.
And that’s it! Some antivirus applications will pick it up as a not-a-virus.bitcoin miner and will require an exception be added. Simple, easy and effective. We would recommend an AMD card of the R9 280x or higher, if your power is cheap, or an R9 3XX or higher if power is more expensive or a nvidia card.
As of this writing, The Nvidia 1080Ti and the AMD vega 64 give the most earnings at lower electricity usage, the R9 290X will earn about two thirds of these two at a greatly higher power usage and noise.
In winter months, consider turning your central heating down, add a couple of GPUs and a good power supply in your main PC rig, and it will warm the room and earn you cash, at the same time, the power cost being less of an issue as its covering your heating.
Note that its best you already own the cards, or in the case of myself, my partner already owned the card Nvidia 1080Ti and mines when its not in use for games and also runs all night, and I bought two after waiting for a bargain to come up to start me out with GPU mining, plus i was building an enthusiast PC rig, so i thought why not!
A platinum rated power supply may seem more expensive, but its cheaper in the long run due to power savings, at 92% efficiency at 80% load. If you are GPU mining, use either an evga, corsair, Antec or similar PSU.
CPU mining typically makes very little cash, but the AMD threadrippers can bring in a bit of spare cash as can the i7 7700k, but don’t consider buying one of these CPUs just to mine with.
GPUs are a safer investment than ASICs, as you have something solid you can sell should the value of any coins drop, etc and have a longer warranty than ASICs, and with the nicehash miner, get paid in Bitcoin. They will tell you your estimated payout date.
If you are new to mining and need a wallet, consider electrum for a PC or mobile wallet. Carefully store the backup seed. You can also get a wallet linked to a real debit card via wirex, here. Getting it from this link will get you 25% off the small fee for the physical plastic debit card.
WARNING: If your PC has a cheap Chinese made power supply, do not run your GPU at full load. It can and probably will melt the thin wires, blow your PSU possibly taking out parts with it, and/or start a fire. Those Chinese PSUs will NOT run high end video cards at full load, whatever their perceived wattage, check this tomshardware article on cheap no name PSUs here.