^ check out the 15 seconds following 5:38 (direct link to that start time) for some really useful mnemonics for the polyrhythms for 2:3 (‘Nice cup of tea’), 3:4 (‘Pass the goddamn butter’), and 4:5 (‘I’m looking for a home to buy’).
Some others can be found at these links (although you really have to hear them, or feel them out against the polyrhythm, to get them right):
[EDIT]
A couple more I figured out by using https://4four.io/ploop:
3:5, emphasis on the 5 — “HEAT UP the CHEESE PIZza PLEASE”
2:5, emphasis on the 5 — “I’VE BEEN CEL-e-BRAT-ING”
3:4 emphasis on the 3, as mentioned above, is “PASS the GODdamn BUTter”. With emphasis on the 4, you can use “I’M LOOKing FOR a CAKE”. It’s pretty interesting to put on a 3:4 rhythm (using eg this excellent tool) and switch between those two.