Should I lump all my funds into one single dividend-paying ETF, or should I buy multiple ones at smaller quantities each?

If you've only got S$30K to invest probably a good idea to invest up to S$5 at a time, once every 2 months over 12 months. It's what we call dollar-cost averaging (DCA). Try and buy the dips if you can

For my own local portfolio, I have a strategy of dollar-cost averaging into the (State Street) STI index tracking ETF, by buying the dips (trading once per quarter). It seems to have worked quite well for me and I get a nice dividend from them every 6 months or so. However, I try and limit this "core holding" ETF to about 30% of my portfolio. The rest of my Singapore portfolio is diversified across a maximum of 10 other ETFs and stocks (all with market caps more than S$1 billion. It works well for me. The more confident you are about picking stocks (and the more time you have for research) the more (or less) you can allocate to the index tracking ETF.

If you're buying one of the local ETFs I recommend you consider the size and liquidity of the fund in question. Lower liquidity means you face bigger trading spreads between buy and sell prices. Also check the management expense ratio (MER) - lower is better. I'd avoid any ETF with an MER more than 0.5%, and I also avoid leveraged products and "synthetic" ETFs.

Some people seem to think the Singapore market is a bit of a boring place to invest these days. However, you can still get very decent returns over the longer-term provided you have the discipline to do a bit of basic research and don't over-trade. I try and limit myself to a maximum of 2 trades per month (but sometimes it's only one).

Dca better to ride out the volatitlity