lekko pijany/wstawiony, podpity, podchmielony

Boring: slightly drunk

• I do karaoke only when I'm slightly drunk.

Use: tipsy or buzzed or tiddly or merry

• I do karaoke only when I'm tipsy.
• tipsy in a song:
• buzzed in a song:

Note that tiddly and merry are both informal British English.