ASICs are needed. Otherwise you are not mining. You are just playing some games, which would be completly legit. You could mine with your CPU just to experiment.
If you don't have access to cheap/free electricity and intend to run a little mining farm, just don't mine. Unfortunately circumstances would be not good for you. You would be burning more and more money every day and you will very unlikely help decentralization.
Generally speaking, If you have the resources and access to brand new machines, then mining is always profitable. If mining is not profitable -> miners turn down machines -> difficulty go down -> mining is profitable again.
However, as you can see, bitcoin hashrate is hitting new highs every day. Profitability today is reaching new and new lows every day. This is due to technological dissemination. Every day better machines are created. This is never ever stopping, which leads to small mining operations failing.
If you live in a cold country, you could use bitcoin miners to heat your house. This way you'd be yield positive regardless of the hashrate evolution.