If all you’re looking to do is to be able to play an instrumental over say a verse or chorus, I’d recommend a simple one-bank looper (like the Ditto X2). You can seamlessly loop a verse+chorus while you’re singing it, then perfectly break off into the solo right after.

In these days, this is commonly accepted by audiences (often expected in my town) as they are all mostly familiar with the advancement of loopers as a musician tool and not a gimmick anymore.

I play covers solo using a vocal harmonizer and seven pedals. I play on cruise ships and the solo gig is great.

My whole act is based on this and it works. I use a Shadowstomp to maintain a kick with my foot. I also hit more than one string as I solo the ones I want, to make it sound like I am playing with another guitarist.

I have a growing case of harmonicas for this. Throw that on a harp holder and do anything slightly better than Dylan and people love it. You should hear me play the harp for the solo in Faithfully! [emoji16]

I do all of the following:

1. Sing the part (I do this in Sister Golden Hair and Drive by Incubus)
2. Play a part that has enough harmonic information that the chords are implied (The Beatles’ All My Loving, Big Star’s Thirteen and Guy Clark’s Boats to Build and The Guitar - gotta love Verlon Thompson; I take great inspiration from this man).
3. Use a looper. I do this for Wish You Were Here, Wichita Lineman and Raul Malo’s Every Little Thing About You. The key is to make sure that the building of the loop isn’t tedious for the audience - it works well and seamlessly on these songs.
4. Play the solo on harp. For Running on Empty and Bowie’s China Girl I use this crutch
5. Skip the solo. It helps if the rest of the song is impressive enough that no one misses the solo too much. This is especially essential if the solo is played on another instrument like saxophone or trumpet.
6. Keep practicing and use Verlon Thompson, Joe Pass, Tuck Andress, Michael Hedges, Monte Montgomery and so many others as inspiration.

This.

You can also get more rhythmically complex with your strumming, picking, and or inversions. You don't necessarily have to play single note stuff for leads, you just need to find a way to make that section stand out.

What do you do for a solo when performing alone?
 

There a lots of ways approach an instrumental section of a song arrangement.

I primarily flat pick or use a hybrid finger style which allows me to incorporate the melody with in the chords and voicings.

As well, I'll keep the groove or pocket going, but break it down to create more of an interlude than a lead break, per se. Sometimes I just play the intro again, which can be a vamp or the last four bars of the song. It all depends on the tune, which it is really what it's all about.

Sometimes I hum or scat a bit of melody.

Here's an nice simple example in the BJ Thomas/Jimmy Capps cover of Don't Worry Baby.
https://youtu.be/oS4srDHnxqA

I use ... acoustic guitar(s),my voice and ... one microphone (if necessary). Seems to work really well.

Of course, I usually only play to audiences that are there listen to the music: "ARTS" (A Right To Silence).

What do you do for a solo when performing alone?
 

Most of the time I don’t do instrumental breaks. On a few of my songs, I do a simple harmonica verse, and one of my songs has a kazoo instrumental! Harmonica is good in small doses and a kazoo should be used very sparingly !