It may be of interest if I share some of the experiences gained through my own investments:
More recently I have sold my shares in Qantas, which I regret.
I sold them at $3.10 having paid $2.95. They are now at $5.81 having lots of ground in a short space of time. An issue of being impatient on my behalf.
Around a year ago I bought Xero for $20 and they are currently trading at $25.75, so a useful gain.
I bought these as the company appears to be gaining momentum and close to becoming profitable. In addition, all the users I have spoken to speak favourably about the product.
Apple and Alphabet
I also purchased some Apple shares and added to my holding in Alphabet (Google).
These two businesses have innovative products, huge cashflows and spend billions annually on R&D. Technology is changing the way we live. I see these shares as a medium to longer term hold.
Sirtex has been disappointing with the price sliding substantially, although it has since recovered some of this ground. I remain hopeful this business will improve with new management at the helm.