Pronouncing non-English names for English speakers

Every time I hear an English speaker trying to pronounce Italian or Spanish words it generally ends up in a complete disaster (especially Italian). For instance, lots of folks haven't realized that the Great Vowel Shift happened, and so try to pronounce vowels as in English, without realizing that 99% of cases, that's wrong.

Also, English speakers have an incredibly hard time not only pronouncing but even understanding the whole concept of geminated consonants, which makes them funnily destroy Italian or Japanese names (gemination is especially important for Italian, where certain words are otherwise undistinguishable, se calo/callo, casa/cassa, pala/palla, ..).

'sz', 'cz' - those are equivalent to 'sh' (shop,shell) and 'ch' (chop, check)

'w' - it's a hard 'v' as in 'very', 'vary'. Always, no exceptions and never anything else, it's Ko-v-alski (Kowalski) and Le-v-ando-v-ski (Lewandowski). This is, I think, the most common mistake when reading polish names because english speakers often soften the 'w' to english 'w' as in 'when'/'why'

'Ł or ł' - that's the thing you think of when you see 'w' in english. It's the same sound as in 'when'/'why'/'when'. It's not a weird accent on 'L', for some reason we don't have 'v' in our alphabet and we moved 'v' sound to 'w' and 'w' sound to 'ł'

ó - it's called 'closed u', the same as normal, open u, pronounced as in 'put'/'dude'. The only difference between open and closed 'u' is in writing, none in speaking

y - a vowel, I don't think the sound exists in english but often 'yyyyyy...' in polish is used as 'ummmmm...' in english

ą, ć, ę, ń, ś, ź, ż - good luck ;)

One thing that makes polish a bit easier is that it's pronunciation is 98% consistent, you need to learn the sound of each letter or digraph once and it will never change so every polish person will pronounce even made-up words in the same way because there's only one way (you may write it incorrectly as in the open/closed u above, or ż/rz, but you will read it back correctly so just don't show anyone how you've written it :) )

I tried to tell the difference between "q" and "ch" here by pronouncing them. As the other comment noted, "ch" is actually a valid pinyin as well, so they are definitely different.

My observation is that for "q" your tongue tip is closer to your teeth and for "ch" your tongue tip is somewhere in the middle of the mouth. Hope that helps.