Personally I use a spreadsheet. I simply made one with an asset column, a cost/profit column, quanity, etc etc.
Using this method i can tell at a glance my average cost/profit per asset and it makes it much easier for me to tell where i need to diversify my portfolio.
You mentioned Poloniex so I'll add it does have an built in analysis page for trades done there..
https://poloniex.com/tradeHistory
I have heard of certain mobile apps as well but have not used any myself other than polo trader just for easier access to current prices.
Yep, can't beat the old fasioned way lol... Mine is like so :)
I just slightly altered one I've had for years for other asssets...
Welcome to steemit !
Cheers guys I think I'm on the right track then. Nothing better than paper even if it is a bit old school. The trade analysis on poloniex is a little skewed as you can buy something for BTC then then sell it later when it is worth more fiat for BTC but at the time BTC has gone up and you will get less BTC than you invested showing a loss but if converted to fiat would be a gain. All the mmore reason to be holding the BTC unless buying to specifically buy other alts.