I am glad you want to write your question so that it won't be seen as subjective. You are right that the wording of the question is key. In fact, one subjective question usually turns into many objective questions. Consider:
What is the best X?
Totally subjective, just going to attract opinions, right? Try:
What factors should I consider when choosing an X?
Better, but still pretty broad. And perhaps you already know what factors you care about. So in that case, can't you ask:
Which weighs more, X.A or X.B?
How likely is an X.A to be cancelled before it happens?
How much faster does X.A build compared to X.B?
These are objective questions. They have right-or-wrong answers. From those answers you may build a picture that answers the original "what should I do?" question you had in your head. But you don't ask that original question on any SE site, instead you ask the smaller objective questions that add up to your decision.
There is another kind of subjective question, and these are welcome only on some sites. On Parenting people ask when to introduce certain foods; on Gardening people ask if it's worth trying to rescue a lawn or should they just re-seed it; on Board and Card Games people ask how to make a game more fun for new players. To word these questions so they attract the good kind of answers, make your question longer. That is, just asking "when should I introduce dairy to my infant?" will not attract good answers. Lay out your situation clearly to reduce speculation. (For example in that case, whether any parents have allergies, or whether someone is pushing hard for the food to be introduced now.) Clarify whether you want opinions, or references to studies and books, or people's experience with their own children. Include any information you've already gathered. The longer and more complete the question, the less likely it is to attract drive-by one-sentence pure-opinion answers. Show you care in the question, and generally answerers will show they care too.