There are many factors to consider when building a baseball card collection. The most important thing is to collect cards that you personally enjoy and find interesting. Here are some general tips on what to look for that can help you start a meaningful collection:

Condition of the card is extremely important. Make sure to only collect cards that are in the best condition possible with no creases, folds, or scratches. The higher the condition of the card, the more valuable it will be long-term. When first starting out, look for cards graded Near Mint or Mint by professional grading companies like PSA or BGS. Card condition is what determines the true value.

Rarity is another big factor that affects value. The scarcer a card is, the more valuable it will become over time as fewer of that card exist in high grades. Look for star players, particularly their rookie cards when they first came onto the scene. Low print run cards or those from defunct card sets can also be very rare. Numbered parallel cards with print runs under 100 of a legendary player are highly sought after.

Vintage cards from the early 20th century before World War 2 are especially desirable and hold their worth well due to the smaller production runs. The older the card is, the greater the odds of condition/centering issues which makes pristine high graded examples quite valuable for collectors. Hall of Fame players from the vintage era will never lose demand.

Modern star players in the prime of their careers are always a safe investment since demand stays strong as long as they keep performing at an elite level. Look for rookies and top prospects too before they break out since their values can spike dramatically with success. Numbered, autographed parallels from within the past 10-15 years have potential for high appreciation.

Full complete sets are fun to put together and can be quite valuable if the set is no longer in print and has demand. The more historically significant the year and the harder the set is to finish in high grades across the board, the more appealing it becomes to devoted collectors.

Autographed cards that have been obtained and certified by a reputable authentication company add another layer of desirability. The bigger the star, and the rarer or more prestigious the signature variant, the higher the collectible factor. Look for on-card autographs whenever possible for maximum authenticity.

Team and league logo/patch cards incorporating pieces of jerseys or hats into the card design have captured the imagination of many collectors in recent decades. Exclusive, low-number parallel versions tied to a player’s career accomplishments are especially prized.

Cards that depict famous and memorable moments from the game immortalized on the cardboard have enriched the sport’s heritage. Iconic cards tied to historic home runs, perfect games, championships and award winners will remain timeless for collectors.

Pack-fresh, unsearched wax boxes or factory sealed cases from popular modern sets have attracted momentum investors looking for growth. Chasing rare hit cards through breaks of these products can be thrilling but also comes with risk.

In the end, choosing cards that stir your personal baseball memories and attachments will lead to the most gratifying collection journey. Whether you focus broadly or specialize tightly, continuously improving condition and deepening the stories behind your pieces are what bring collections to life. Enjoy the hunt through dealers, auctions and your own finds over many years!