When to sell a stock ? at 100% profit or or time frame ?

Hi ,
I would like to know view of senior investor on how to build a portfolio in current market. When to sell a stock ? Should it be based on % of profit or on time frame ?

I have few shares which are giving 50-100 % profit in last 3 months . But I am sure that these will give much more in coming time (say 3 years ).
Not very sure how to proceed ?
Please advise me. I would like to build a portfolio for long term.

Thanks

There are no fixed rules.
How much time do you have available? DO you trade actively? Do you understand market technicals?

Stocks should be bought when there's a reason to buy and sold when there's a reason to sell. Your own individual performance of holding a stock should have NOTHING to do with your decision to buy or sell.

I usually sell shares @ 5% profits, time period less then 15 days. But without any SL and due to this stucked in couple of scrips.