A tip for Mandarin second tone: start high
Mandarin's second tone is harder to pronounce correctly than many learners realise. Beginners tend to focus a lot on getting third tone correct as it seems the most unnatural tone for people not used to tonal languages. While the standard description of second tone as “high rising” (ˊ) sounds simple enough, it can be tricky to pronounce this tone correctly in fluent speech.
A tip for getting second tone correct is to remember that it's called “high rising” and not just “rising”. More simply: start higher to get second tone right.
Starting higher and going up from there will help you avoid the common mistake of turning second tone (ˊ) into third tone (ˇ). People learning Mandarin tend to start second tone low to give it plenty of space to rise up, but the low starting pitch risks it being mistaken for third tone.
Third tone is called “falling rising”, which is an accurate description but skips over another important feature of third tone, which is that it's overall lower in pitch than the others. Native Mandarin speakers are sensitive to the general low pitch of third tone, and in fluent speech this is often the main feature of third tone: it's just generally low rather than having an obvious dip and climb in pitch.
If you start second tone at a low pitch, it's likely to end up sounding like third tone instead. You can avoid this mistake by focusing on both “high” and “rising” for second tone. Start quite high in pitch and go up a little bit.
You can see this quite often in words that have a second tone syllable followed by a first tone. For example the word 蓝天 lántiān (“blue skies”). Learners are prone to getting the tones wrong on this and ending up pronouncing it as lǎntiān instead.
You can increase your chances of getting second tone right by starting higher.