After sailing on over 55 cruises, there are 6 things I never waste my money on when I'm at sea

Most onboard spa treatments don't feel like a great value.

Spa treatments might seem like a tempting way to relax during your cruise, but I've rarely found them worth the high price.

After splurging on massages across multiple cruise lines, I've always left disappointed. My husband is a sucker for the spa, but after we spent more than $400 on a couples massage during a cruise to New Zealand, even he agreed it wasn't worth the splurge.

Although the massages themselves were perfectly fine, the upselling afterward always makes me uncomfortable. Therapists often encourage you to buy expensive products, but the pushy sales tactics can quickly offset the post-massage relaxation.

Instead, I'd rather splurge on a thermal spa pass. It's often cheaper than a couples massage and it lets me enjoy the spa's amenities throughout the cruise without feeling pressured to buy anything.

Drink packages never feel like a good value for us.

Although unlimited cocktails might sound appealing, purchasing a drink package has actually made my cruises less relaxing.

I've splurged on drink packages with Royal Caribbean and Carnival, but I can't drink enough alcohol to justify the cost. Often, they can cost upward of $70 per person, per day.

Whenever I've purchased one, I've found myself constantly calculating how many drinks I need to order just to break even. This completely defeats the convenience of having a drink package in the first place.

I also don't have the stamina to drink consistently throughout a cruise, especially on longer itineraries.

Even when my husband and I cruised with friends who had drink packages, we struggled to get our money's worth. Instead, we ended up drinking more than we normally would, which left us feeling bloated and hungover.

Now, the only time I'll cruise with a drink package is when it's bundled with a fare, such as with Norwegian's Free at Sea or Celebrity's All Included.

On-board art auctions and pricey paintings don't tempt me.

Almost every cruise ship I've been on has had a dedicated art gallery where guests can browse and purchase artwork to bring home. Throughout the sailing, the galleries host art auctions and entice guests with the promise of free Champagne.

I've never been tempted to attend one — not even for a free drink. Buying expensive artwork isn't my style, and I've heard horror stories from cruisers who regret getting caught up in the excitement of a competitive auction.

If I'm going to buy artwork during a trip, I'd rather support local artists in port. In fact, many of my walls are covered with beautiful pieces of art from all over the world.

I don't bother with professional photos when I can take my own.

On most cruise lines, photographers repeatedly ask you to pose for pictures, whether that's during embarkation, while you're eating at a specialty restaurant, or as you're stepping off the gangway in port.

These photos can be fun keepsakes, but each printed photo usually costs around $25 — and that often doesn't include a digital copy.

Photo packages can be an even bigger expense, often costing more than $100. Some cruisers buy a package before they even know whether they'll like enough photos to make it worthwhile.

Although this is a convenient way to get posed photos, I don't think professional cruise photos are worth the price. My phone takes excellent pictures, and there's almost always another guest who's happy to snap a quick group photo for me.

If room service costs extra, I'm skipping it.

I love ordering room service for a complimentary continental breakfast, especially during busy port mornings. But when it comes to paying extra for room service, I always skip it.

Continental breakfast is perfect for enjoying coffee and a pastry before heading ashore. However, most cruise lines charge a flat delivery fee for other orders. For instance, Royal Caribbean charges $7.95 per delivery for room service, which can add up quickly over the course of your cruise.

For me, it's just not worth the extra cost. There's almost always a complimentary dining venue open somewhere on the ship for snacks, late-night bites, or pizza.

I'd rather take a short walk than pay to have food delivered to my cabin.

Laundry services can get pricey, and I don't mind washing clothes at sea as needed.

I've taken plenty of longer itineraries, including a 15-night repositioning cruise from Sydney to Singapore. Laundry can pile up on these long sailings, but I've never paid to have the cruise line do it for me.

Cost is the biggest reason I avoid using this service while cruising. For example, on my most recent Celebrity cruise, prices ranged from about $12 to launder a dress to nearly $24 for a suit. A full laundry bag can easily turn into a hefty bill.

Instead, I pack a few travel-size laundry-detergent packets and hand-wash smaller items in my cabin sink or shower. I'll typically wash undergarments and socks in warm water before hanging them to dry in the shower.

After hand-washing my clothes for 100 days during Semester at Sea in college, washing a few items in my cruise cabin is no big deal.