I would go for long term trading. I can say that its really good and applicable for me. I used to learn from being a panic seller and managed to become a short term or day trader. But I'm upgraded right now and I can say thay long term trading is applicable for me because I can handle my emotion and I'm not the same anymore.
these two strategies are not separate from each other so you don't exactly need to only choose one for your trading strategies. you can do both and also remember that different markets require different type of approach.
for example you can do day trading in both altcoin and bitcoin market but long term investment only works with bitcoin and not a single altcoin is good for that.
Just follow the trend and you shall succeed, now that bitcoin is getting its good value most altcoins are currently on dump, you can buy now and expect to make profit again once bitcoin starts to neutralize, it's a hard job to do really if you are doing it for short term trades.
However, if you look for long term trade, technique that I used is I buy at dip and keep it longer, it gives me success doing it, just be patient to wait.