I chose to acknowledge gifts that have been created for me by recognising the kindness and thought that went into it, rather than the end product. For me, thoughtfulness is the most important part to me not how beautiful I think it is (or isn’t - how often do we lie to our kids!!). What we talk about is what we measure and for me the end product is not the most important part of the process.
I choose to acknowledge the thoughtfulness and kindness involved in creating and giving the gift. I might comment on different aspects of the art (e.g. “you used so many colours”) or the process (e.g. “that bit was tough but you kept going”) but very rarely give judgement (e.g. avoiding “It's so pretty”). Our words tell our children what is important to us, so in turn this tells them what should be important to them. If we choose to priotise the end product that is what children will focus on (increasing anxiety), not the process of creating or giving, which is really what we ought to celebrate (increasing self-worth and highlighting important values linked to happiness).