Yes, CEF, not an ETF, though they are inclined and the tips here also are valid for the ETFs as well.
Every closed-end-fund is a part of a sector, has its holdings which can be stocks and bonds and the instrument is correlated with the sector's ETF/ETFs.
The research approach is mainly fundamental. Technical analysis is minimal in which you can watch the volumes and apply the VWAP indicator.
When first choosing a CEF I open CEF Connect and there I search for specific information:
- Premium/Discount level;
- Does it give a dividend and what is the rate/distribution;
- The 3 - 3-month Z score;
- The NAV according to price;
- The portfolio characteristic - the holdings, the main sector holding, country allocation;
I use also Seeking Alpha and I have a couple of favorite authors that write on the CEF/ETF topic. I'll leave them in the comments if someone is asking. I use the site to check in-depth details for the dividend and SEC fillings.
I hope this info is of help!