What cultural faux pas should I try to avoid making in Panajachel?

"It is important to be respectful of local customs and traditions when visiting Panajachel. It is important to dress modestly and to avoid public displays of affection. It is also important to be aware of the local language and to be respectful when speaking to locals. Additionally, it is important to be aware of the local religious beliefs and to avoid making any comments that could be seen as offensive or disrespectful. Finally, it is important to be aware of the local customs regarding tipping and to be respectful when bargaining for goods and services," mentioned another expat when asked about moving to Panajachel, Guatemala.