earth-shattering forecasts

I find that whenever I do a reading, or a few consecutive readings, a bunch of trivial stuff comes up like taking a nap comes up as 4 swords, cutting coupons comes up as 4 pentacles, going for a jog comes up as 5 wands, and so on. The World card comes up and it only meant that I had a nice conversation w a friend. How do you forecast life-changing events like a marriage, a relationship commitment, etc.?

The Tarot lends itself to multi-layered meanings, so it would depend on one's view. Also how the cards hit one's view at the moment whether it's a mundane meaning, at another level or involves more than one simultaneously. That something as apparently trivial as a nap is confirmed is also significant, depending on how much one needs a nap or "time out"--I've had occasions to read 4-Swords as getting or needing a nap.
4-Wands can refer to a relationship or a commitment; the number 2 minor arcanas; also various Swords cards. It is difficult to take a card out of context of surrounding cards, as often the latter may modify or influence the meanings of other cards in a spread. Seeing the general tone of a spread--as in the presence of Majors or lack of same; the prevailing suit or lack of a suit; the court cards; or just the impressions or feelings prompted--may provide clues as to the nature of the subject. It may also depend on the focus of the querent &/or the reader at the time the cards are thrown.
There are spreads designed to deal with relationship issues or you could make up one of your own. The book "Power Tarot" by Trish MacGregor & Phyllis Vega has many different spreads including those referring to relationships.